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Javascript Boolean
JavaScript Boolean is an object that represents value in two types : true or false.  If value parameter is omitted or is 0, -0, null, false, undefined, mpty string (""), or NaN the object has an initial value of false.

You can create the JavaScript Boolean object by Boolean() syntax as given below.
var val = new Boolean(value);
Example :
<html>
<head>
<title>Javascript Boolean</title>
</head>
<body>
    
<script type="text/javascript">

  var YES = true;
  var NO = false;
  document.write(true +'<br />');//true 
  document.write(false);//false  
 
</script>
 
</body>
</html>
Output :

true

false

Boolean Value is True or False :
<html>
<head>
<title>Javascript Booleans Value is True or False</title>
</head>
<body> 
 
<h4>With a "Real" Value is True</h4>
<p id="true_bool"></p><br>
<h4>Without a "Real" is False</h4>
<p id="text_1"></p>
<p id="text_2"></p>
<p id="text_3"></p>
<p id="text_4"></p>
<p id="text_5"></p>
<p id="text_6"></p>
<p id="text_7"></p>
    
<script type="text/javascript">
 
 
var bool_1 = Boolean(54);
var bool_2 = Boolean(2.89);
var bool_3 = Boolean(-20);
var bool_4 = Boolean("JavaScript");
var bool_5 = Boolean('false');
var bool_6 = Boolean(4 + 5 + 2.88);
document.getElementById("true_bool").innerHTML =
"54 is : " + bool_1 + "<br>" +
"2.89 is : " + bool_2 + "<br>" +
"-20 is : " + bool_3 + "<br>" +
"This string is : " + bool_4 + "<br>" +
"String 'false' is : " + bool_5 + "<br>" +
"This Value is : " + bool_6;
 
 
var boolean_1 = new Boolean(0);
document.getElementById("text_1").innerHTML = boolean_1;
 
var boolean_2 = new Boolean(-0);
document.getElementById("text_2").innerHTML = boolean_2;
 
var boolean_3 = new Boolean("");
document.getElementById("text_3").innerHTML = boolean_3;
 
 
var boolean_4 = new Boolean(undefined);
document.getElementById("text_4").innerHTML = boolean_4;
 
var boolean_5 = new Boolean(null);
document.getElementById("text_5").innerHTML = boolean_5;
 
 
var boolean_6 = new Boolean(false);
document.getElementById("text_6").innerHTML = boolean_6;
 
var boolean_7 = new Boolean(NaN); 
document.getElementById("text_7").innerHTML = boolean_7;
 
</script>
 
</body>
</html>
Output :

With a "Real" Value is True

54 is : true

2.89 is : true

-20 is : true

This string is : true

String 'false' is : true

This Value is : true


Without a "Real" is False

false

false

false

false

false

false

false

Javascript Boolean Methods
Method Description
toSource() Returns the source of Boolean object as a string.
toString() Returns a string representing the specified boolean object.
valueOf() Returns the value of the Boolean object.
JavaScript boolean object : toSource() method :
<html>
<head>
<title>JavaScript boolean object : toSource() method</title>
</head>
<body> 
 
 
<script type="text/javascript"> 
 
  bool_inf = new Boolean(0);  
  document.write(bool_inf.toSource()); 
 
</script>  
 
</body>
</html>
Output :
JavaScript boolean object : toString() method :
<html>
<head>
<title>JavaScript boolean object : toString() method</title>
</head>
<body> 
 
 
<script type="text/javascript">  

  boolean_object = new Boolean(true);  
  if(boolean_object.toString() == "true")  
  alert("Both are equal....");  
  else  
  alert("Both are not equal");
 
</script>
 
</body>
</html>
Output :
JavaScript boolean object : valueOf() method :
<html>
<head>
<title>JavaScript boolean object : valueOf() method</title>
</head>
<body> 
 
 
<script type="text/javascript">  

  bool_val = new Boolean(1);  
  document.write(bool_val.valueOf());  

</script>  
 
</body>
</html>
Output :

true