How to a count a specific digit in a number with javascript

Question

I am trying to write a block of code which will separate digits (with modulus operator) in a number first and count how many digit "6" are there in the number.

I tried so many things but I think I have logic problem with the way I think.

output = [];

var count = 0;


while (a > 0){
  output.push(a % 10);
  a = Math.floor(a/10);
  if(a == 6){
      count++;
    }
}

When I run this code on Safari, It shows the entered number as it is, but it shows "0" for the variable count.

Since this is a homework, I am not allowed to convert the number to a string. — Ihap Subasi
– Ihap Subasi, Commented Oct 23, 2019 at 0:15
var chars = a+"".split(''); should return a array of chars which you can now count by a simple for next loop. — Thomas Ludewig
– Thomas Ludewig, Commented Oct 23, 2019 at 0:18

Nikhil · Accepted Answer · 2019-10-23 00:24:05Z

3

Math.floor(a/10) doesn't give the current digit. a % 10 gives the current digit.

You have check if the current digit a % 10 is 6.

Live Example:

let output = [];
let count = 0;
let a = 1667;

while (a > 0) {
  let digit = a % 10;
  output.push(digit);
 
  if (digit == 6) {
    count++;
  }
    
  a = Math.floor(a / 10);
}

console.log(count);

answered Oct 23, 2019 at 0:24

Nikhil

6,68110 gold badges36 silver badges74 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Stratubas · Accepted Answer · 2019-10-23 00:25:33Z

1

You know the last digit, so you can subtract it and divide with 10, instead of using Math.floor.

let number = 1626364656; // has 5 sixes
let sixesCount = 0;
while (number > 0) {
    const digit = number % 10;
    if (digit === 6) {
        sixesCount++;
    }
    number = (number - digit) / 10;
}
console.log('Found', sixesCount, 'sixes.'); // "Found 5 sixes."

answered Oct 23, 2019 at 0:25

Stratubas

3,0671 gold badge16 silver badges18 bronze badges

Collectives™ on Stack Overflow

How to a count a specific digit in a number with javascript

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related