javascriptregexfrontend

can Regex .test() in JavaScript test the whole string?

Everything seems to point that .test() is supposed to be able to test an entire string but I can't get it to work:

var exp = new RegExp("^([a-z])$");
console.log( exp.test('hello') );

console.log( /^([a-z0-9])$/.test('abc12') );

Both return false when it's supposed to be true;

here's a link to a demo: http://jsbin.com/ibokem/1/

Solution

  • Character classes match single characters. You need to repeat them:

    var exp = new RegExp("^([a-z]*)$");
console.log( exp.test('hello') );

console.log( /^([a-z0-9]*)$/.test('abc12') );

    Or if you want to require at least one character, use + instead of *.

    Also, if you're just using the patterns with test, you can get rid of the parentheses: 

    var exp = new RegExp("^[a-z]*$");
console.log( exp.test('hello') );

console.log( /^[a-z0-9]*$/.test('abc12') );