JavaScript: Number of occurrences of each letter in specified string

Last update on May 30 2022 10:07:05 (UTC/GMT +8 hours)

JavaScript Function: Exercise-17 with Solution

Write a JavaScript function to get the number of occurrences of each letter in specified string.

Pictorial Presentation:

JavaScript: Number of occurrences of each letter in specified string

Sample Solution: -

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Number of occurrences of each letter in specified string</title>
</head>
<body>

JavaScript Code:

function Char_Counts(str1) {
var uchars = {};
str1.replace(/\S/g, function(l){uchars[l] = (isNaN(uchars[l]) ? 1 : uchars[l] + 1);});
return uchars;
}
console.log(Char_Counts("The quick brown fox jumps over the lazy dog"));

Sample Output:

{"T":1,"h":2,"e":3,"q":1,"u":2,"i":1,"c":1,"k":1,"b":1,"r":2,"o":4,"w":1,"n":1,"f":1,"x":1,"j":1,"m":1,"p":1,"s":1,"v":1,"t":1,"l":1,"a":1,"z":1,"y":1,"d":1,"g":1}

Flowchart:

Live Demo:

See the Pen JavaScript - Number of occurrences of each letter in specified string-function-ex- 17 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript function to extract unique characters from a string.
Next: Write a function for searching JavaScript arrays with a binary search.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04