How to select and use the last digits if number is above 1000

Question

I have a very simple code and function. My problem is: I want to select the last digit of a given number, which I did but when I want to use it, it simply won't work.

My job in this function is to make numbers more readable, so for example: if number is 1, output must be 1st; if number is 3, output must be 3rd; if number is 402 output must be 402nd.

function humanizeChar (number) {  
var lastOne = number.toString().split('').pop();
  if (lastOne === 1) {
    return number + 'st';
  } else if (lastOne === 2) {
    return number + 'nd';
  } else if (lastOne === 3) {
    return number + 'rd';
  } else {
    return number + 'th';
  } 
}
console.log(humanizeChar(1131)); // my output is 1131th

`lastOne` is a string. `'1' === 1` is `false`. – Felix Kling Jan 10 '17 at 15:20 — Felix Kling, Jan 10 '17 at 15:20
@FelixKling Thanks, i thought i changed that... – Duca Jan 10 '17 at 15:25 — Duca, Jan 10 '17 at 15:25

score 1 · Accepted Answer · answered Jan 10 '17 at 15:20

You are trying to compare a string (lastOne) to a number with strict equality ===, that compares the value and the type. You can use simple equality == or change the numbers to strings:

function humanizeChar (number) {  
  var lastOne = number.toString().split('').pop();
  console.log(lastOne);
  if (lastOne === '1') {
    return number + 'st';
  } else if (lastOne === '2') {
    return number + 'nd';
  } else if (lastOne === '3') {
    return number + 'rd';
  } else {
    return number + 'th';
  } 
}
console.log(humanizeChar(1131)); // my output is 1131th

Thanks for your help, i have accepted your answer because of your quick response — Duca, Jan 10 '17 at 15:34

Rai Vu · Answer 2 · 2017-01-10T15:24:25.033

1

Try this, seem you compare the output string with the number:

function humanizeChar (number) {  
var lastOne = number.toString().split('').pop();
  if (lastOne === "1") {
    return number + 'st';
  } else if (lastOne === "2") {
    return number + 'nd';
  } else if (lastOne === "3") {
    return number + 'rd';
  } else {
    return number + 'th';
  } 
}
console.log(humanizeChar(1131)); // my output is 1131th

edited Jan 10 '17 at 15:24

answered Jan 10 '17 at 15:20

Rai Vu

1,595
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Your answer will be more useful to others if you explain what the problem is and how your solutions solves it. – Felix Kling Jan 10 '17 at 15:22

score 1 · Answer 3 · edited May 23 '17 at 12:24

Your problem is, that you are comparing strings with numbers, using the === operator. As stated in this very good answer on SO:

The identity (===) operator behaves identically to the equality (==) operator except no type conversion is done, and the types must be the same to be considered equal.

So you could either convert your lastOne manually to a number (e.g. using parseInt(lastOne)) or use the == operator instead. Or you could compare lastOne to string literals ('1','2',...) instead.

score 1 · Answer 4 · answered Jan 10 '17 at 15:25

1

JavaScript Comparison Operators Operator Description == equal to === equal value and equal type

in your case the correct operator is '=='

answered Jan 10 '17 at 15:25

ottis79

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Vishal Thakur · Answer 5 · 2017-01-10T15:37:04.707

You need to make some changes in your code like below:-

function humanizeChar (number) {
number = 7882;          //just give some number for checking
var lastOne = number.toString().split('').pop();
//console.log(lastOne);
  if (lastOne == 1) {
    return number + 'st';
  } else if (lastOne == 2) {
    return number + 'nd';
  } else if (lastOne == 3) {
    return number + 'rd';
  } else {
    return number + 'th';
  } 
}
console.log(humanizeChar());

score 1 · Answer 6 · answered Jan 10 '17 at 15:36

We also need to account the 2nd from last digit. For example, 101 should be one hundred and first instead of one hundred and oneth.

//Improving from Ori Drori's answer
function humanizeChar (number) {
    var numStrs = number.toString().split('');
    var lastOne = numStrs.pop();
    var isSeondFromLastGreaterThanZero = (numStrs.length > 0 && numStrs.pop() !== '0');
    var suffix = "th";

    if (!isSeondFromLastGreaterThanZero) {
        if (lastOne === '1') {
            suffix = 'st';
        } else if (lastOne === '2') {
            suffix = 'nd';
        } else if (lastOne === '3') {
            suffix = 'rd';
        }
    }

    return number.toString() + suffix;

}
console.log(humanizeChar(1131)); // my output is 1131th
console.log(humanizeChar(1101)); // 1101st
console.log(humanizeChar(2)); // 2nd

How to select and use the last digits if number is above 1000

6 Answers6