empty in javascript code example

Example 1: javascript empty function

const func = () => {};
// Or
const func = Function();

Example 2: javascript if string empty

// Test whether strValue is empty or is None
if (strValue) {
    //do something
}
// Test wheter strValue is empty, but not None 
if (strValue === "") {
    //do something
}

Example 3: empty string in javascript

var s; // undefined
var s = ""; // ""
s.length // 0

Example 4: empty javascript

function sum(a, a, c) { // !!! syntax error
  'use strict';
  return a + a + c; // wrong if this code ran
}