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Gabriel Prates
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README-pt_BR.md
132
README-pt_BR.md
@ -25,37 +25,37 @@ Imagine que você está escrevendo uma aplicação e quer colocar regras para qu
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A expressão regular acima aceita as strings `john_doe`, `jo-hn_doe` e `john12_as`. Ela não aceita `Jo` porque essa string contém letras maiúsculas e também é muito curta.
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## Table of Contents
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## Sumário
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- [Basic Matchers](#1-basic-matchers)
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- [Meta character](#2-meta-characters)
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- [Full stop](#21-full-stop)
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- [Character set](#22-character-set)
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- [Negated character set](#221-negated-character-set)
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- [Repetitions](#23-repetitions)
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- [The Star](#231-the-star)
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- [The Plus](#232-the-plus)
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- [The Question Mark](#233-the-question-mark)
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- [Braces](#24-braces)
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- [Character Group](#25-character-group)
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- [Alternation](#26-alternation)
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- [Escaping special character](#27-escaping-special-character)
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- [Anchors](#28-anchors)
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- [Caret](#281-caret)
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- [Dollar](#282-dollar)
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- [Shorthand Character Sets](#3-shorthand-character-sets)
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- [Lookaround](#4-lookaround)
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- [Positive Lookahead](#41-positive-lookahead)
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- [Negative Lookahead](#42-negative-lookahead)
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- [Positive Lookbehind](#43-positive-lookbehind)
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- [Negative Lookbehind](#44-negative-lookbehind)
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- [Combinações Básicas](#1-basic-matchers)
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- [Metacaracteres](#2-meta-characters)
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- [Ponto final](#21-full-stop)
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- [Conjunto de caracteres](#22-character-set)
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- [Conjunto de caracteres negados](#221-negated-character-set)
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- [Repetições](#23-repetitions)
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- [O Asterisco](#231-the-star)
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- [O Sinal de Adição](#232-the-plus)
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- [O Ponto de Interrogação](#233-the-question-mark)
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- [Chaves](#24-braces)
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- [Grupo de Caracteres](#25-character-group)
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- [Alternância](#26-alternation)
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- [Escapando Caracteres Especiais](#27-escaping-special-character)
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- [Âncoras](#28-anchors)
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- [Acento Circunflexo](#281-caret)
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- [Sinal de Dólar](#282-dollar)
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- [Forma Abreviada de Conjunto de Caracteres](#3-shorthand-character-sets)
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- [Olhar ao Redor](#4-lookaround)
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- [Lookahead Positivo](#41-positive-lookahead)
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- [Lookahead Negativo](#42-negative-lookahead)
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- [Lookbehind Positivo](#43-positive-lookbehind)
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- [Lookbehind Negativo](#44-negative-lookbehind)
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- [Flags](#5-flags)
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- [Case Insensitive](#51-case-insensitive)
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- [Global search](#52-global-search)
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- [Multiline](#53-multiline)
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- [Bonus](#bonus)
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- [Indiferente à Maiúsculas](#51-case-insensitive)
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- [Busca Global](#52-global-search)
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- [Multilinhas](#53-multiline)
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- [Bônus](#bonus)
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## 1. Basic Matchers
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## 1. Combinações Básicas
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A regular expression is just a pattern of characters that we use to perform search in a text. For example, the regular expression
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`the` means: the letter `t`, followed by the letter `h`, followed by the letter `e`.
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@ -76,7 +76,7 @@ case-sensitive so the regular expression `The` would not match the string `the`.
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[Test the regular expression](https://regex101.com/r/1paXsy/1)
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## 2. Meta Characters
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## 2. Metacaracteres
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Meta characters are the building blocks of the regular expressions. Meta characters do not stand for themselves but instead are
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interpreted in some special way. Some meta characters have a special meaning and are written inside square brackets.
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@ -90,16 +90,16 @@ The meta characters are as follows:
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|*|Matches 0 or more repetitions of the preceding symbol.|
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|+|Matches 1 or more repetitions of the preceding symbol.
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|?|Makes the preceding symbol optional.|
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|{n,m}|Braces. Matches at least "n" but not more than "m" repetitions of the preceding symbol.|
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|{n,m}|Chaves. Matches at least "n" but not more than "m" repetitions of the preceding symbol.|
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|(xyz)|Character group. Matches the characters xyz in that exact order.|
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|||Alternation. Matches either the characters before or the characters after the symbol.|
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|||Alternância. Matches either the characters before or the characters after the symbol.|
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|\|Escapes the next character. This allows you to match reserved characters <code>[ ] ( ) { } . * + ? ^ $ \ |</code>|
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|^|Matches the beginning of the input.|
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|$|Matches the end of the input.|
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## 2.1 Full stop
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## 2.1 Ponto final
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Full stop `.` is the simplest example of meta character. The meta character `.` matches any single character. It will not match return
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Ponto final `.` is the simplest example of meta character. The meta character `.` matches any single character. It will not match return
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or newline characters. For example, the regular expression `.ar` means: any character, followed by the letter `a`, followed by the
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letter `r`.
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@ -109,7 +109,7 @@ letter `r`.
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[Test the regular expression](https://regex101.com/r/xc9GkU/1)
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## 2.2 Character set
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## 2.2 Conjunto de caracteres
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Character sets are also called character class. Square brackets are used to specify character sets. Use a hyphen inside a character set to
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specify the characters' range. The order of the character range inside square brackets doesn't matter. For example, the regular
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@ -129,7 +129,7 @@ A period inside a character set, however, means a literal period. The regular ex
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[Test the regular expression](https://regex101.com/r/wL3xtE/1)
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### 2.2.1 Negated character set
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### 2.2.1 Conjunto de caracteres negados
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In general, the caret symbol represents the start of the string, but when it is typed after the opening square bracket it negates the
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character set. For example, the regular expression `[^c]ar` means: any character except `c`, followed by the character `a`, followed by
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@ -141,12 +141,12 @@ the letter `r`.
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[Test the regular expression](https://regex101.com/r/nNNlq3/1)
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## 2.3 Repetitions
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## 2.3 Repetições
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Following meta characters `+`, `*` or `?` are used to specify how many times a subpattern can occur. These meta characters act
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differently in different situations.
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### 2.3.1 The Star
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### 2.3.1 O Asterisco
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The symbol `*` matches zero or more repetitions of the preceding matcher. The regular expression `a*` means: zero or more repetitions
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of preceding lowercase character `a`. But if it appears after a character set or class then it finds the repetitions of the whole
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@ -169,7 +169,7 @@ zero or more spaces.
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[Test the regular expression](https://regex101.com/r/gGrwuz/1)
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### 2.3.2 The Plus
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### 2.3.2 O Sinal de Adição
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The symbol `+` matches one or more repetitions of the preceding character. For example, the regular expression `c.+t` means: lowercase
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letter `c`, followed by at least one character, followed by the lowercase character `t`.
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@ -180,7 +180,7 @@ letter `c`, followed by at least one character, followed by the lowercase charac
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[Test the regular expression](https://regex101.com/r/Dzf9Aa/1)
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### 2.3.3 The Question Mark
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### 2.3.3 O Ponto de Interrogação
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In regular expression the meta character `?` makes the preceding character optional. This symbol matches zero or one instance of
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the preceding character. For example, the regular expression `[T]?he` means: Optional the uppercase letter `T`, followed by the lowercase
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@ -198,7 +198,7 @@ character `h`, followed by the lowercase character `e`.
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[Test the regular expression](https://regex101.com/r/kPpO2x/1)
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## 2.4 Braces
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## 2.4 Chaves
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In regular expression braces that are also called quantifiers are used to specify the number of times that a
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character or a group of characters can be repeated. For example, the regular expression `[0-9]{2,3}` means: Match at least 2 digits but not more than 3 (
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@ -225,7 +225,7 @@ the comma the regular expression `[0-9]{3}` means: Match exactly 3 digits.
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[Test the regular expression](https://regex101.com/r/Sivu30/1)
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## 2.5 Character Group
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## 2.5 Grupo de Caracteres
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Character group is a group of sub-patterns that is written inside Parentheses `(...)`. As we discussed before that in regular expression
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if we put a quantifier after a character then it will repeat the preceding character. But if we put quantifier after a character group then
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@ -239,7 +239,7 @@ We can also use the alternation `|` meta character inside character group. For e
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[Test the regular expression](https://regex101.com/r/tUxrBG/1)
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## 2.6 Alternation
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## 2.6 Alternância
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In regular expression Vertical bar `|` is used to define alternation. Alternation is like a condition between multiple expressions. Now,
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you may be thinking that character set and alternation works the same way. But the big difference between character set and alternation
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@ -253,7 +253,7 @@ or lowercase character `c`, followed by lowercase character `a`, followed by low
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[Test the regular expression](https://regex101.com/r/fBXyX0/1)
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## 2.7 Escaping special character
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## 2.7 Escapando Caracteres Especiais
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Backslash `\` is used in regular expression to escape the next character. This allows to to specify a symbol as a matching character
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including reserved characters `{ } [ ] / \ + * . $ ^ | ?`. To use a special character as a matching character prepend `\` before it.
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@ -267,16 +267,16 @@ expression `(f|c|m)at\.?` means: lowercase letter `f`, `c` or `m`, followed by l
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[Test the regular expression](https://regex101.com/r/DOc5Nu/1)
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## 2.8 Anchors
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## 2.8 Âncoras
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In regular expressions, we use anchors to check if the matching symbol is the starting symbol or ending symbol of the
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input string. Anchors are of two types: First type is Caret `^` that check if the matching character is the start
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character of the input and the second type is Dollar `$` that checks if matching character is the last character of the
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input string. Âncoras are of two types: First type is Acento Circunflexo `^` that check if the matching character is the start
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character of the input and the second type is Sinal de Dólar `$` that checks if matching character is the last character of the
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input string.
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### 2.8.1 Caret
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### 2.8.1 Acento Circunflexo
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Caret `^` symbol is used to check if matching character is the first character of the input string. If we apply the following regular
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Acento Circunflexo `^` symbol is used to check if matching character is the first character of the input string. If we apply the following regular
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expression `^a` (if a is the starting symbol) to input string `abc` it matches `a`. But if we apply regular expression `^b` on above
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input string it does not match anything. Because in input string `abc` "b" is not the starting symbol. Let's take a look at another
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regular expression `^(T|t)he` which means: uppercase character `T` or lowercase character `t` is the start symbol of the input string,
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@ -294,9 +294,9 @@ followed by lowercase character `h`, followed by lowercase character `e`.
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[Test the regular expression](https://regex101.com/r/jXrKne/1)
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### 2.8.2 Dollar
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### 2.8.2 Sinal de Dólar
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Dollar `$` symbol is used to check if matching character is the last character of the input string. For example, regular expression
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Sinal de Dólar `$` symbol is used to check if matching character is the last character of the input string. For example, regular expression
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`(at\.)$` means: a lowercase character `a`, followed by lowercase character `t`, followed by a `.` character and the matcher
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must be end of the string.
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@ -312,7 +312,7 @@ must be end of the string.
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[Test the regular expression](https://regex101.com/r/t0AkOd/1)
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## 3. Shorthand Character Sets
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## 3. Forma Abreviada de Conjunto de Caracteres
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Regular expression provides shorthands for the commonly used character sets, which offer convenient shorthands for commonly used
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regular expressions. The shorthand character sets are as follows:
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@ -327,7 +327,7 @@ regular expressions. The shorthand character sets are as follows:
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|\s|Matches whitespace character: `[\t\n\f\r\p{Z}]`|
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|\S|Matches non-whitespace character: `[^\s]`|
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## 4. Lookaround
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## 4. Olhar ao Redor
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Lookbehind and lookahead sometimes known as lookaround are specific type of ***non-capturing group*** (Use to match the pattern but not
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included in matching list). Lookaheads are used when we have the condition that this pattern is preceded or followed by another certain
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@ -337,12 +337,12 @@ by `$` character. Following are the lookarounds that are used in regular express
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|Symbol|Description|
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|:----:|----|
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|?=|Positive Lookahead|
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|?!|Negative Lookahead|
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|?<=|Positive Lookbehind|
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|?<!|Negative Lookbehind|
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|?=|Lookahead Positivo|
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|?!|Lookahead Negativo|
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|?<=|Lookbehind Positivo|
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|?<!|Lookbehind Negativo|
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### 4.1 Positive Lookahead
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### 4.1 Lookahead Positivo
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The positive lookahead asserts that the first part of the expression must be followed by the lookahead expression. The returned match
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only contains the text that is matched by the first part of the expression. To define a positive lookahead, parentheses are used. Within
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@ -357,7 +357,7 @@ followed by letter `h`, followed by letter `e`. In parentheses we define positiv
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[Test the regular expression](https://regex101.com/r/IDDARt/1)
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### 4.2 Negative Lookahead
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### 4.2 Lookahead Negativo
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Negative lookahead is used when we need to get all matches from input string that are not followed by a pattern. Negative lookahead
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defined same as we define positive lookahead but the only difference is instead of equal `=` character we use negation `!` character
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@ -370,7 +370,7 @@ input string that are not followed by the word `fat` precedes by a space charact
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[Test the regular expression](https://regex101.com/r/V32Npg/1)
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### 4.3 Positive Lookbehind
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### 4.3 Lookbehind Positivo
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Positive lookbehind is used to get all the matches that are preceded by a specific pattern. Positive lookbehind is denoted by
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`(?<=...)`. For example, the regular expression `(?<=[T|t]he\s)(fat|mat)` means: get all `fat` or `mat` words from input string that
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@ -382,7 +382,7 @@ are after the word `The` or `the`.
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[Test the regular expression](https://regex101.com/r/avH165/1)
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### 4.4 Negative Lookbehind
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### 4.4 Lookbehind Negativo
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Negative lookbehind is used to get all the matches that are not preceded by a specific pattern. Negative lookbehind is denoted by
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`(?<!...)`. For example, the regular expression `(?<!(T|t)he\s)(cat)` means: get all `cat` words from input string that
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@ -396,16 +396,16 @@ are not after the word `The` or `the`.
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## 5. Flags
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Flags are also called modifiers because they modify the output of a regular expression. These flags can be used in any order or
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Flags (sinalizadores) are also called modifiers because they modify the output of a regular expression. These flags can be used in any order or
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combination, and are an integral part of the RegExp.
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|Flag|Description|
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|:----:|----|
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|i|Case insensitive: Sets matching to be case-insensitive.|
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|g|Global Search: Search for a pattern throughout the input string.|
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|m|Multiline: Anchor meta character works on each line.|
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|m|Multilinhas: Anchor meta character works on each line.|
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### 5.1 Case Insensitive
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### 5.1 Indiferente à Maiúsculas
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The `i` modifier is used to perform case-insensitive matching. For example, the regular expression `/The/gi` means: uppercase letter
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`T`, followed by lowercase character `h`, followed by character `e`. And at the end of regular expression the `i` flag tells the
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@ -424,7 +424,7 @@ the whole input string.
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[Test the regular expression](https://regex101.com/r/ahfiuh/1)
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### 5.2 Global search
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### 5.2 Busca Global
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The `g` modifier is used to perform a global match (find all matches rather than stopping after the first match). For example, the
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regular expression`/.(at)/g` means: any character except new line, followed by lowercase character `a`, followed by lowercase
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@ -443,7 +443,7 @@ string.
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[Test the regular expression](https://regex101.com/r/dO1nef/1)
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### 5.3 Multiline
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### 5.3 Multilinhas
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The `m` modifier is used to perform a multi-line match. As we discussed earlier anchors `(^, $)` are used to check if pattern is
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the beginning of the input or end of the input string. But if we want that anchors works on each line we use `m` flag. For example, the
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@ -466,7 +466,7 @@ line. And because of `m` flag now regular expression engine matches pattern at t
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[Test the regular expression](https://regex101.com/r/E88WE2/1)
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## Bonus
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## Bônus
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* *Positive Integers*: `^\d+$`
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* *Negative Integers*: `^-\d+$`
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