Common native methods of JS

JavaScript Pow () method

The POW () method returns the value of the Y-power of X

Grammar

Math.pow (x, y)

Parameters	Description
X	Necessary. Base Must be a number.
Y	Necessary. The power number. Must be a number.

return value

The Y power of X.

Description

If the result is an imaginary number or a negative number, the method returns NaN. If a floating-point overflow is caused by an exponent that is too large, the method returns Infinity.

Instance

In the following example, we will apply the POW () to a different number combination:

<script type= "Text/javascript" >document.write (Math.pow (0,0) + "<br/>") document.write (Math.pow (0,1) + " <br/> ") document.write (Math.pow (+) +" <br/> ") document.write (Math.pow (1,10) +" <br/> ") document.write (Math.pow (2,3) + "<br/>") document.write (Math.pow ( -2,3) + "<br/>") document.write (Math.pow (2,4) + "<br/>") document.write (Math.pow ( -2,4) + "<br/>") </script>

Output:

10118-81616

JavaScript parseint () function

JavaScript Global Objects

Definition and usage

The parseint () function parses a string and returns an integer.

Grammar

parseint (stringradix)

Parameters	Description
String	Necessary. The string to be parsed.
Radix	Optional. Represents the cardinality of the number to parse. The value is between 2 and 36. If this argument is omitted or its value is 0, the number is parsed based on 10. If it starts with "0x" or "0X", it will have a base of 16. If the parameter is less than 2 or greater than 36, parseint () returns NaN.

return value

Returns the parsed number.

Description

When the value of the parameter radix is 0, or if the parameter is not set, parseint () determines the cardinality of the number based on string .

For example, if string starts with "0x", parseint () resolves the remainder of the string to a 16-binary integer. If string starts with 0, then ECMAScript V3 allows an implementation of parseint () to parse subsequent characters into octal or hexadecimal digits. If string starts with a number from 1 to 9, parseint () parses it into a decimal integer.

Hints and Notes

Note: Only the first number in a string is returned.

Note: Spaces at the beginning and end are allowed.

Tip: If the first character of a string cannot be converted to a number, parsefloat () returns NaN.

Instance

In this example, we will use parseint () to parse the different strings:

parseint ("10");//returns 10PARSEINT ("19", 10);//returns 10+9 parseint ("11", 2),//returns 3 (2+1) parseint ("17", 8);//returns 15 (8+7) parseint ("1f", 16);//Return to 16+15 parseint ("010");//undecided: return 10 or 8

JavaScript number () function

JavaScript Global Objects

Definition and usage

The number () function converts the value of the object to a digit.

Grammar

Number (object)

Parameters	Description
Object	Necessary. JavaScript object.

return value

If the parameter is a Date object, number () returns the milliseconds from January 1, 1970 to the present.

The number () function returns NaN if the value of the object cannot be converted to numbers.

Instance

In this example, we will try to convert different objects to numbers:

<script type= "Text/javascript" >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");d ocument.write ( Number(test1) + "<br/>");d ocument.write ( Number(test2)+ "<br/>");d ocument.write ( Number(test3) + "<br/>");d ocument.write ( Number(test4) + "<br/>");d ocument.write ( Number(test5)+ "<br/>");</script>

Output:

101256657776588999NaN

Common native methods of JS