# JavaScript: Find the number of trailing zeros in the decimal representation of the factorial of a given number

## JavaScript Basic: Exercise-112 with Solution

Write a JavaScript program to find the number of trailing zeros in the decimal representation of the factorial of a given number.

Pictorial Presentation:

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title> Find the number of trailing zeros in the decimal representation of the factorial of a given number</title>
<body>

</body>
</html>

JavaScript Code:

function trailing_zeros_factorial(n) {
var result = 0;
for (var i = 5; i <= n; i += 5) {
var num = i;
while (num % 5 === 0) {
num /= 5;
result++;
}
}
return result;
}

console.log(trailing_zeros_factorial(8))
console.log(trailing_zeros_factorial(9))
console.log(trailing_zeros_factorial(10))

Sample Output:

1
1
2

Flowchart:

ES6 Version:

function trailing_zeros_factorial(n) {
let result = 0;
for (let i = 5; i <= n; i += 5) {
let num = i;
while (num % 5 === 0) {
num /= 5;
result++;
}
}
return result;
}

console.log(trailing_zeros_factorial(8))
console.log(trailing_zeros_factorial(9))
console.log(trailing_zeros_factorial(10))

Live Demo:

See the Pen javascript-basic-exercise-112 by w3resource (@w3resource) on CodePen.

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﻿

## JavaScript: Tips of the Day

Example:

str
.split(';')
.map(v => v.split('='))
.reduce((acc, v) => {
acc[decodeURIComponent(v[0].trim())] = decodeURIComponent(v[1].trim());
return acc;
}, {});
console.log(parseCookie('foo=bar; equation=E%3Dmc%5E2')); // { foo: 'bar', equation: 'E=mc^2' }

Output:

[object Object] {
equation: "E=mc^2",
foo: "bar"
}

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