Is there a standard function to check for null, undefined, or blank variables in JavaScript?

Question

Is there a universal JavaScript function that checks that a variable has a value and ensures that it\'s not undefined or null? I\'ve got this code,

Answer 1

function notEmpty(value){
  return (typeof value !== 'undefined' && value.trim().length);
}

it will also check white spaces (' ') along with following:

• null ,undefined ,NaN ,empty ,string ("") ,0 ,false