JavaScript - Count all the numbers with unique digits in a range
JavaScript Math: Exercise-109 with Solution
Write a JavaScript program that accepts a number (n) and counts all numbers with unique digits of length p within a specified range.
Range: 0 <= p < 10n
Example:
When n = 1, numbers with unique digits (10) between 0 and 9 are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
When n = 2, numbers with unique digits (91) between 0 and 100 are 0,1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15 …..99 except 11, 22, 33, 44, 55, 66, 77, 88 and 99.
Test Data:
(1) -> 10
(2) -> 91
Sample Solution:
HTML Code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JavaScript program to Count all numbers with unique digits in a range</title>
</head>
<body>
</body>
</html>
JavaScript Code:
function test(n) {
if(n===0){
return 1;
}
var result = 10;
var temp =9;
for(var i=1; i<n; i++){
temp *= 10-i
result+=temp
}
return result;
}
n = 1
console.log("Range: "+n+" to 10")
console.log("Numbers with unique digits in the said range: "+test(n));
n = 2
console.log("Range: "+n+" to 10")
console.log("Numbers with unique digits in the said range: "+test(n));
Sample Output:
Range: 1 to 10 Numbers with unique digits in the said range: 10 Range: 2 to 10 Numbers with unique digits in the said range: 91
Flowchart:

Live Demo:
See the Pen javascript-math-exercise-109 by w3resource (@w3resource) on CodePen.
Improve this sample solution and post your code through Disqus
Previous: Power of four.
Next: Sum of two square numbers equal to an integer.
What is the difficulty level of this exercise?
Test your Programming skills with w3resource's quiz.
JavaScript: Tips of the Day
Shorten an array using its length property
A great way of shortening an array is by redefining its length property.
let array = [0, 1, 2, 3, 4, 5, 6, 6, 8, 9] array.length = 4 // Result: [0, 1, 2, 3]
Important to know though is that this is a destructive way of changing the array. This means you lose all the other values that used to be in the array.
Ref: https://bit.ly/2LBj213
- Weekly Trends
- Java Basic Programming Exercises
- SQL Subqueries
- Adventureworks Database Exercises
- C# Sharp Basic Exercises
- SQL COUNT() with distinct
- JavaScript String Exercises
- JavaScript HTML Form Validation
- Java Collection Exercises
- SQL COUNT() function
- SQL Inner Join
- JavaScript functions Exercises
- Python Tutorial
- Python Array Exercises
- SQL Cross Join
- C# Sharp Array Exercises