JavaScript Number()Function
JavaScript Global Functions
Definition and Usage
The Number() function converts the value of an object to a number.
If the value of the object cannot be converted to a number, the Number() function returns NaN.
Syntax
Number(object)
| Parameters | Description |
|---|---|
| object | Optional. A JavaScript object. If no parameter is provided, it returns 0. |
Browser Support
All major browsers support the Number() function
Tips and Notes
Note:If the parameter is a Date object, Number() returns the number of milliseconds from January 1, 1970 to the present.
Examples
Examples
Convert different objects to numbers:
<script>
var test1= new Boolean(true);
var test2= new Boolean(false);
var test3= new Date();
var test4= new String("999");
var test5= new String("999 888");
document.write(Number(test1)+ "<br>");
document.write(Number(test2)+ "<br>");
document.write(Number(test3)+ "<br>");
document.write(Number(test4)+ "<br>");
document.write(Number(test5)+ "<br>");
</script>
var test1= new Boolean(true);
var test2= new Boolean(false);
var test3= new Date();
var test4= new String("999");
var test5= new String("999 888");
document.write(Number(test1)+ "<br>");
document.write(Number(test2)+ "<br>");
document.write(Number(test3)+ "<br>");
document.write(Number(test4)+ "<br>");
document.write(Number(test5)+ "<br>");
</script>
The output result of the above example:
Try it Yourself »
JavaScript Global Functions Other Extensions