Return true/false for a matched/not matched regex

Question

I have this regex on Javascript

var myS = \"00 - ??:??:?? - a\";
var removedTL = myS.match(/^(\\d\\d) - (\\?\\?|10|0\\d):(\\?\\?|[0-5]\\d):(\\?\\?|[0-5]\\d)          


        

Answer 1

The more appropriate function here might be RegExp.test, which explicitly gives you true or false.

console.log(/lolcakes/.test("some string"));
// Output: false

console.log(/lolcakes/.test("some lolcakes"));
// Output: true

Answer 2

var myS = "00 - ??:??:?? - a";
var patt = new RegExp("^(\d\d) - (\?\?|10|0\d):(\?\?|[0-5]\d):(\?\?|[0-5]\d) - (.*)");
var removedTL = patt.test(myS);

removedTL will hold a boolean value true if matched, false if not matched

Answer 3

Use a double logical NOT operator.

return !!removedTL;

This will convert to true/false depending on if matches are found.

No matches gives you null, which is converted to false.

One or more matches gives you an Array, which is converted to true.

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As an alternative, you can use .test() instead of .match().

/^(\d\d) - (\?\?|10|0\d):(\?\?|[0-5]\d):(\?\?|[0-5]\d) - (.*)/.test( myS );

...which gives you a boolean result directly.

Answer 4

The match method will return null if there is no match.

Answer 5

Since I also prefer using match you could do the following workaround to get a Boolean result:

var myS = "00 - ??:??:?? - a"
var removedTL = myS.match(/^(\d\d) - (\?\?|10|0\d):(\?\?|[0-5]\d):(\?\?|[0-5]\d) - (.*)/) != null