# JavaScript: Check whether the first numeric argument is divisible by the second one

## JavaScript fundamental (ES6 Syntax): Exercise-201 with Solution

Write a JavaScript program to check whether the first numeric argument is divisible by the second one.

• Use the modulo operator (%) to check if the remainder is equal to 0.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2
const isDivisible = (dividend, divisor) => dividend % divisor === 0;

console.log(isDivisible(6, 3));
console.log(isDivisible(5, 3));
console.log(isDivisible(100, 10));
console.log(isDivisible(0, 3));

Sample Output:

true
false
true
true

Pictorial Presentation:

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-201-1 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

﻿

## JavaScript: Tips of the Day

Checking if a key exists in a JavaScript object?

Checking for undefined-ness is not an accurate way of testing whether a key exists. What if the key exists but the value is actually undefined?

var obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!

You should instead use the in operator:

"key" in obj // true, regardless of the actual value

If you want to check if a key doesn't exist, remember to use parenthesis:

!("key" in obj) // true if "key" doesn't exist in object
!"key" in obj   // ERROR!  Equivalent to "false in obj"

Or, if you want to particularly test for properties of the object instance (and not inherited properties), use hasOwnProperty:

obj.hasOwnProperty("key") // true

Checking for undefined-ness is not an accurate way of testing whether a key exists. What if the key exists but the value is actually undefined? var obj = { key: undefined }; obj["key"] !== undefined // false, but the key exists! You should instead use the in operator: "key" in obj // true, regardless of the actual value If you want to check if a key doesn't exist, remember to use parenthesis: !("key" in obj) // true if "key" doesn't exist in object !"key" in obj // ERROR! Equivalent to "false in obj" Or, if you want to particularly test for properties of the object instance (and not inherited properties), use hasOwnProperty: obj.hasOwnProperty("key") // true For performance comparison between the methods that are in, hasOwnProperty and key is undefined.

Ref: https://bit.ly/2CFNp1X