javascript if not empty code example

Example 1: javascript not empty array not string

if (Array.isArray(array) && array.length) {
    // array exists and is not empty
}

Example 2: js if string not empty

if (!str.length) { ...

Example 3: 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 4: empty string in javascript

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

Example 5: javascript check if empty

//check if string is undefined 
if (typeof myVar === 'undefined'){
  console.log("I am not defined");
}

//check if string is empty, null, or 0
var emptyString="";
if (emptyString) {
    console.log("im not empty");
}