JavaScript: Letter count within a string

Last update on May 30 2022 10:01:54 (UTC/GMT +8 hours)

JavaScript Function: Exercise-22 with Solution

Write a JavaScript function that accepts two arguments, a string and a letter and the function will count the number of occurrences of the specified letter within the string.

Sample arguments: 'w3resource.com', 'o'
Expected output: 2

Pictorial Presentation:

JavaScript: Letter count within a string

Sample Solution: -

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Letter count within a string</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function char_count(str, letter) 
{
 var letter_Count = 0;
 for (var position = 0; position < str.length; position++) 
 {
    if (str.charAt(position) == letter) 
      {
      letter_Count += 1;
      }
  }
  return letter_Count;
}

console.log(char_count('w3resource.com', 'o'));

Sample Output:

Flowchart:

Live Demo:

See the Pen JavaScript - Letter count within a string-function-ex- 22 by w3resource (@w3resource) on CodePen.

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Previous: Write a JavaScript function to get all possible subset with a fixed length (for example 2) combinations in an array.
Next: Write a JavaScript function to find the first not repeated character.

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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