Add meta characters table

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Zeeshan Ahmed 2017-07-23 04:31:03 +01:00
parent 06328f01a5
commit 199f0374f1

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@ -30,7 +30,22 @@ The regular expression `123` matches the string "123". The regular expression is
# 2. Meta Characters
Meta characters are the building blocks of the regular expressions. Some meta characters have a special meaning that are written inside the square brackets.
Meta characters are the building blocks of the regular expressions. Some meta characters have a special meaning that are written inside the square brackets. The meta character are as follows:
|Meta character|Description|
|:----:|----|
|**.**|Period matches any single character except a line break.|
|**[ ]**|Character class. Matches any character contained between the square brackets.|
|**[^ ]**|Negated character class. Matches any character that is not contained between the square brackets|
|*****|Matches 0 or more repetitions of the preceding symbol.|
|**+**|Matches 1 or more repetitions of the preceding symbol.
|**?**|Makes the preceding symbol optional.|
|**{n}**|Braces. Matches “n” repetitions of the preceding symbol.|
|**(xyz)**|Character group. Matches the characters xyz in that exact order.|
|**|**|Alternation. Matches either the characters before or the characters after the symbol.|
|**\**|Escapes the next character. This allows you to match reserved characters `[ ] ( ) { } . * + ? ^ $ \ |`|
|**^**|Matches the beginning of the input.|
|**$**|Matches the end of the input.|
# 2.1 Full stop