JavaScript: Formats a number to a human-readable string

JavaScript String: Exercise-15 with Solution

Write a JavaScript function that format a number in a human-readable string with the correct suffix, such as 1st, 2nd, 3rd, etc.

Test Data:
console.log(humanize_format());
console.log(humanize_format(1));
console.log(humanize_format(8));
console.log(humanize_format(301));
console.log(humanize_format(402));
"1st"
"8th"
"301st"
"402nd"

Sample Solution:

JavaScript Code:

// Define a function named humanize_format that takes a number num as input
humanize_format = function humanize(num) {
   // Check if the num parameter is undefined, return undefined if so
   if(typeof(num) == "undefined") return;
  // Check if the number modulo 100 falls within the range 11-13, return the number followed by "th" if true
  if(num % 100 >= 11 && num % 100 <= 13)
        return num + "th";
        
        // Switch statement to handle different cases based on the last digit of the number
        switch(num % 10) {
            // Return the number followed by "st" if the last digit is 1
            case 1: return num + "st";
            // Return the number followed by "nd" if the last digit is 2
            case 2: return num + "nd";
            // Return the number followed by "rd" if the last digit is 3
            case 3: return num + "rd";
        }
        // Return the number followed by "th" for all other cases
        return num + "th";
    }
// Output the result of calling the humanize_format function with different test cases
console.log(humanize_format());  
console.log(humanize_format(1));  
console.log(humanize_format(8));  
console.log(humanize_format(301));  
console.log(humanize_format(402));
 

Output:

undefined
1st
8th
301st
402nd

Explanation:

In the exercise above,

• The function "humanize_format()" takes a number as input and returns a human-readable format for ordinal numbers.
• It first checks if the input number is undefined and returns undefined if so.
• It then checks if the number modulo 100 falls within the range 11-13. If true, it returns the number followed by "th".
• If the number is not in the special case range, it uses a switch statement to handle different cases based on the last digit of the number:
• If the last digit is 1, it returns the number followed by "st".
• If the last digit is 2, it returns the number followed by "nd".
• If the last digit is 3, it returns the number followed by "rd".
• For all other cases, it returns the number followed by "th".
• The code then outputs the results of calling the "humanize_format()" function with different test cases to the console.

Flowchart:

Live Demo:

See the Pen JavaScript Formats a number to a human-readable string - string-ex-15 by w3resource (@w3resource) on CodePen.

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