JavaScript Math.ceil() Method

1. Syntax of JavaScript Math.ceil() Method
2. Example 1: Use the Math.ceil() Method to Get Nearest Integer of a Number in Decimal Form
3. Example 2: Use Math.ceil() and Math.round() to Get and Compare the Rounded Numbers
4. Example 3: Use the Math.ceil() Method on a String Value
5. Example 4: Use the Math.ceil() Method on Addition of Two Values
6. Example 5: Use the Math.ceil() Method on an Empty Value

The Math.ceil() method takes any number and round it to the nearest integer without decreasing the value. In JavaScript, ceil is used for Math objects, and the syntax can’t be changed.

Syntax of JavaScript Math.ceil() Method

Math.ceil(x);

Parameters

Return

This method returns the nearest integer of the number after rounding it up.

Example 1: Use the Math.ceil() Method to Get Nearest Integer of a Number in Decimal Form

We use the method Math.ceil() to get a rounded-up integer of a number in decimal form to increase the value. In the example below, we used the Math.ceil() method to get the nearest integer of a number.

let num = 0.5;
console.log(Math.ceil(num));

Output:

1

Example 2: Use Math.ceil() and Math.round() to Get and Compare the Rounded Numbers

We convert the decimal numbers to the nearest integer using Math.ceil() and Math.round() methods. However, both methods give different outputs if the number in decimal form is less than .5.

In this example, we have used the ceil() and round() methods to round 1.2 to the nearest integer.

let num = 1.2;
console.log(Math.ceil(num));
console.log(Math.round(num));

Output:

2
1

Example 3: Use the Math.ceil() Method on a String Value

When we use the string value as a parameter of the Math.ceil() method, it always returns the NaN (Not a Number) that users also can see in the output of the example below.

let str = "Delft";
let ceilValue = Math.ceil(str);
console.log(ceilValue);
console.log(Math.ceil("stack"));

Output:

NaN
NaN

Example 4: Use the Math.ceil() Method on Addition of Two Values

Users can use the Math.ceil() method to add two or more numbers after rounding up the numbers.

In the example below, we have taken two number values and added them differently. In the sum1, we have stored the ceil value of the sum of both numbers, and in the sum2, we have stored the sum of two different numbers after rounding them up separately.

let num1 = 10.2;
let num2 = 10.4;
let sum1 = Math.ceil(num1+num2);
let sum2 = Math.ceil(num1) + Math.ceil(num2);
console.log(sum1);
console.log(sum2);

Output:

21
22

Example 5: Use the Math.ceil() Method on an Empty Value

We will understand what happens if we pass the empty value as a parameter of the Math.ceil() method via a single example.

In the example below, we have taken 4 values: Infinity, the empty string "", undefined, and NaN. In the output, users see that the method returns the same for the Infinity value.

For the undefined, and NaN value method returns the NaN value, and for the empty string "", it returns 0.

let val = Infinity;
let ceilValue = Math.ceil(val);
console.log(ceilValue);
console.log(Math.ceil(NaN));
console.log(Math.ceil(""));
let num = undefined;
console.log(Math.ceil(num));

Output:

Infinity
NaN
0
NaN

The Math.ceil() method is supported in all browsers.