'IsNullOrWhitespace' in JavaScript?

Question

Is there a JavaScript equivalent to .NET\'s String.IsNullOrWhitespace so that I can check if a textbox on the client-side has any visible text in it?

I\'d rather do

Answer 1

Try this out

/**
  * Checks the string if undefined, null, not typeof string, empty or space(s)
  * @param {any} str string to be evaluated
  * @returns {boolean} the evaluated result
*/
function isStringNullOrWhiteSpace(str) {
    return str === undefined || str === null
                             || typeof str !== 'string'
                             || str.match(/^ *$/) !== null;
}

You can use it like this

isStringNullOrWhiteSpace('Your String');