javascript is not empty code example

Example 1: is var is not blank then display value in javascript

if(data !== null && data !== '') {
   // do something
}

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: javascript check for null variables

var myVar=null;

if(myVar === null){
    //I am null;
}

if (typeof myVar === 'undefined'){
    //myVar is undefined
}

Example 5: javascript check if variable is empty

if( value ) {
  //
}

/**
* This will evaluate to true if value is not:
* null
* undefined
* NaN
* empty string ("")
* 0
* false
*/

Example 6: empty string in javascript

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