Match any numbers that have one or more digits in a phone number.
Match a number containing two, three or four digits.
Non-capturing group : match a group of characters twice
Capturing group : match a group of characters twice
Match a four-digit number.
Use word boundaries to find a time that has the format hh:mm.
Match a 4-digit number surrounded by non-word characters.
Check if the string 'Hello JS!' contains the word 'JS'.
Search for ES\n6
Match the first digit of each line in a multiline string.
Match only the first digit of a multiline string.
Match the start and end of an input string.
Match the end of the string.
Match the start of the string.
Search for ES6
Match all non-digits in a phone number, using the \D inverse class and replace all non-digits with a null string.
Search for O2