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Suppose I want a regex to match "Jump over this bridge FOOL" as well as "Jump over this bridge". How do I make "FOOL" optional (0 or 1 occurrence)?
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Basically (0+1)* mathes any sequence of ones and zeroes. So, in your example (0+1)*1(0+1)* should match any sequence that has 1. It would not match 000 , but it would match 010 , 1 , 111 etc. (0+1) means 0 OR 1.
$ means "Match the end of the string" (the position after the last character in the string).
You can repeat expressions with an asterisk or plus sign. A regular expression followed by an asterisk ( * ) matches zero or more occurrences of the regular expression. If there is any choice, the first matching string in a line is used.
When a character is followed by ? in a regular expression it means to match zero or one instance of the character. So X? matches an 'X' if there is one in the string, but otherwise matches nothing.
You can use the ? mark to specify the occurrence of a group as optional (occurs 0 or 1 time), or you can also use curly braces with min/max values as 0 and 1, so the answer is:
Jump over this bridge( FOOL)? or
Jump over this bridge( FOOL){0,1} If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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