The Boolean.valueOf() is an inbuilt function in javascript which is used to return a boolean value either “true” or “false” depending upon the value of the specified boolean object.
It returns false if the string argument is null otherwise it returns true.
Syntax:
boolean.valueOf()
Parameter:
Here nothing as a parameter is passed.
Return Values:
It returns a boolean value either “true” or “false” depending upon the value of the specified boolean object.
Let’s see some JavaScript code on this boolean.toString() function:
// 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. console.log(obj.valueOf()); |
Output:
> "true"
// 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. console.log(obj.valueOf()); |
Output:
> "true"
// 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. console.log(obj.valueOf()); |
Output:
> "true"
// 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. console.log(obj.valueOf()); |
Output:
> "true"
// 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. console.log(obj.valueOf()); |
Output:
> "true"
// 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. console.log(obj.valueOf()); |
Output:
> "false"
// 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. console.log(obj.valueOf()); |
Output:
> "false"
- Here the value as geeksforgeeks gives error because this value is not defined only true and false has been predefined.
// 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());
Output:
Error: geeksforgeeks is not defined
- 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.
// 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());
Output:
Error: Invalid or unexpected token
Errors and Exceptions:
Application:
This function’s application is to return a boolean value of either “true” or “false” depending upon the value of the object given.
Let’s see JavaScript program on this application:
// 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. console.log(obj.valueOf()); |
Output:
> "true"
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