JavaScript Boolean valueOf() Method

Last Updated : 27 Jun, 2020

Below is the example of Boolean valueOf() method.

Example:

<script>
  // Here Boolean object obj 
  // is created for the value 27
  var obj = new Boolean(27);
  
  // Here boolean.valueOf() function is 
  // used for the created object obj.
  document.write(obj.valueOf());

Output:
```
true
```

The boolean.valueOf() method is used to return a boolean value either “true” or “false” depending upon the value of the specified boolean object.

Syntax:

boolean.valueOf()

Parameter: This method does not accept any parameter.

Return value: It returns a boolean value either “true” or “false” depending upon the value of the specified boolean object.

More codes for the above method are as follows:

Program 1:

<script>
  // Here Boolean object obj is created 
  // for the value true.
  var obj = new Boolean(true);
  
  // Here boolean.valueOf() function is 
  // used for the created object obj.
  document.write(obj.valueOf());
</script>

Output:

true

Program 2:

<script>
  // Here Boolean object obj is
  // created for the value 1.
  var obj = new Boolean(1);
  
  // Here boolean.valueOf() function 
  // is used for the created object obj.
  document.write(obj.valueOf());
</script>

Output:

true

Program 3:

<script>
  // Here Boolean object obj is 
  // created for the value -1.
  var obj = new Boolean(-1);
  
  // Here boolean.valueOf() function
  // is used for the created object obj.
  document.write(obj.valueOf());
</script>

Output:

true

Program 4:

<script>
  // Here Boolean object obj is 
  // created for the value 1.2
  var obj = new Boolean(1.2);
  
  // Here boolean.valueOf() function 
  // is used for the created object obj.
  document.write(obj.valueOf());
</script>

Output:

true

Program 5:

<script>
  // Here Boolean object obj is 
  // created for the value as string "gfg"
  var obj = new Boolean("gfg");
  
  // Here boolean.valueOf() function is 
  // used for the created object obj.
  document.write(obj.valueOf());
</script>

Output:

true

Program 6:

<script>
  // Here Boolean object obj is created for the value false.
  var obj = new Boolean(false);
  
  // Here boolean.valueOf() function is
  // used for the created object obj.
  document.write(obj.valueOf());
</script>

Output:

false

Program 7:

<script>
  // Here Boolean object obj is created 
  // for the value zero (0)
  var obj = new Boolean(0);
  
  // Here boolean.valueOf() function is 
  // used for the created object obj.
  document.write(obj.valueOf());
</script>

Output:

false

Errors and Exceptions: Check the console for this Programs.

Program 1: Here the value as geeksforgeeks gives an error because this value is not defined only true and false has been predefined.

<script>
  // Here Boolean object obj is created 
  // for the value geeksforgeeks.
  var obj = new Boolean(geeksforgeeks);
  
  // Here boolean.valueOf() function is
  // used for the created object obj.
  console.log(obj.valueOf());
</script>

Output:

Error: geeksforgeeks is not defined

Program 2: Here complex number can not be taken as the parameter only integer values and string can be taken as the parameter that is why it returns error.

<script>
  // Here Boolean object obj is created 
  // for the value such as complex number 1+2i
  var obj = new Boolean(1 + 2i);
  
  // Here boolean.valueOf() function is
  // used for the created object obj.
  console.log(obj.valueOf());