JavaScript Math Object

JavaScript provides an Inbuilt Math object to handle mathematic tasks with numbers, and in this tutorial, we will learn how to use some of the Math object properties and methods to perform those tasks.

The Math object

The Math is a static object which means we do not need to initialize it with the new constructor. Instead, we can directly use Math all properties and method using the Math name, without creating its object.

Math Properties Constant values

The Math object supports many properties that are used to represent constant values. There are 8 number constant values provided as the Math properties.

Syntax

Math.property_name

Example

<script>
    euler = Math.E;   // return Euler's number
    pi  = Math.PI;   // retrun pi value
    sqrt2   = Math.SQRT2;  // retrun square root of 2 
    sqrt1_2   = Math.SQRT1_2;   // return square root of 1/2
    log2   = Math.LN2; // return logarithm of 2
    log10 = Math.LN10;   //retrun logarithm of 10
    log2e  = Math.LOG2E;  //retrun base 2 log value of E
    log10e  = Math.LOG10E;  // return base 10 log value of E

    console.log(euler);
    console.log(pi);
    console.log(sqrt2);
    console.log(sqrt1_2);
    console.log(log2);
    console.log(log10);
    console.log(log2e);
    console.log(log10e);   
</script>

Output

2.718281828459045
3.141592653589793
1.4142135623730951
0.7071067811865476
0.6931471805599453
2.302585092994046
1.4426950408889634
0.4342944819032518

Math Methods

Now let's see some of the Math important methods that we often use during JavaScript programming.

Number to Integer

There are 4 common Math methods that can be used to round up a floating-point or decimal number to an integer number.

• Math.round(number)
• Math.ceil(number)
• Math.floor(number)
• Math.trunc(number)

Math.round() method

The round(num) method accepts a number num as a parameter and return the nearest integer value of the number num .

Example

<script>
    console.log(Math.round(1.5));  //2
    console.log(Math.round(20.3));  //20
    console.log(Math.round(3.9));   //4
    console.log(Math.round(-3.1));   //-3
    console.log(Math.round(3.1));   //3
    console.log(Math.round(3));     //3
</script>

Math.ceil() method

The ceil(num) method also accepts a number num as a parameter and round up the number to its nearest large Integer number.

Example

<script>
    console.log(Math.ceil(1.5));  //2
    console.log(Math.ceil(20.3));  //21
    console.log(Math.ceil(3.9));   //4
    console.log(Math.ceil(-3.1));   //-3
    console.log(Math.ceil(3.1));   //4
    console.log(Math.ceil(3.0));     //3
</script>

Math.floor() method

The Math.floor(num) method accepts a number num as a parameter and return a round down integer Number of num .

Example

<script>
    console.log(Math.floor(1.5));  //1
    console.log(Math.floor(20.3));  //20
    console.log(Math.floor(3.9));   //3
    console.log(Math.floor(-3.1));   //-4
    console.log(Math.floor(3.1));   //3
    console.log(Math.floor(3.0));     //3
</script>

Math.trunc() method

The trunc(num.ddd) method remove the decimal part and only return the integer part of num.ddd . We can use this method to convert any decimal number to its integer value without rounding the number.

Example

<script>
    console.log(Math.trunc(1.5));  //1
    console.log(Math.trunc(20.3));  //20
    console.log(Math.trunc(3.9));   //3
    console.log(Math.trunc(-3.1));   //-3
    console.log(Math.trunc(3.1));   //3
    console.log(Math.trunc(3.0));     //3
</script>

Math.sign() method

The sign(num) method is used to check the positive, negative or null sign on the number num . If the value of num is negative the sign() method will return -1 if the value of num is positive the sign() will return 1 for num 0 value it returns 0.

Example

<script>
    console.log(Math.sign(-2));   //-1
    console.log(Math.sign(2));    //1
    console.log(Math.sign(0));    //0
</script>

Math.pow() method

The Math.pow(a,b) is used to find the power of a raise to the b .

Example

<script>
    console.log(Math.pow(3,2));   //9
    console.log(Math.pow(4,3));    //64
    console.log(Math.pow(5,2));    //25
</script>

Math.sqrt() method

The sqrt(num) method will return the square root of number num .

Example

<script>
    console.log(Math.sqrt(64));   //8
    console.log(Math.sqrt(50));    //7.0710678118654755
    console.log(Math.sqrt(100));    //10
</script>

Math.abs() method

The abs(num) method returns the absolute positive value of the specified parameter num .

Example

<script>
    console.log(Math.abs(-64));   //64
    console.log(Math.abs(-50));    //50
    console.log(Math.abs(-100));    //100
</script>

Math.sin() method

The sin(angle_radian) method return the sin value (-1 to 1) of the specified radian angle. By default, the sin() method accepts value in radian but we can also convert the radian value to the degree with the following formula. Angle in radians = Angle in degrees x PI / 180.

Example

<script>
    // in radian
    console.log(Math.sin(90));   //0.8939966636005579

    //in degree
    console.log(Math.sin(90*Math.PI/180));    //1
</script>

<script>
    // in radian
    console.log(Math.cos(180));   //-0.5984600690578581

    //in degree
    console.log(Math.cos(180*Math.PI/180));    //-1
</script>

<script>
    console.log(Math.min(12,34,2,354,35,64,63,632,67));   //2
</script>

<script>
    console.log(Math.max(12,34,2,354,35,64,63,632,67));   //632
</script>

<script>
    console.log(Math.random());   //0.31252884998756825
    console.log(Math.random());   //0.6562255988576251
    console.log(Math.random());   //0.8190211236154034
</script>

<script>
    // generate random number between 0 to 10(exclusive)
    console.log(Math.random()*10);   //9.143861799011312
    console.log(Math.random()*10);   //3.0111929359964784
    console.log(Math.random()*10);   //9.495673571174885
</script>

<script>
    console.log(Math.log(1));   //0
</script>

<script>
    console.log(Math.log2(64));   //6
</script>

<script>
    console.log(Math.log10(100));   //2
</script>