JavaScript: Extract unique characters from a string

Last update on May 30 2022 10:01:12 (UTC/GMT +8 hours)

JavaScript Function: Exercise-16 with Solution

Write a JavaScript function to extract unique characters from a string.

Example string : "thequickbrownfoxjumpsoverthelazydog"
Expected Output : "thequickbrownfxjmpsvlazydg"

Sample Solution: -

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Extract unique character from a string</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function unique_char(str1)
{
 var str=str1;
 var uniql="";
 for (var x=0;x < str.length;x++)
 {

 if(uniql.indexOf(str.charAt(x))==-1)
  {
  uniql += str[x];  
  
   }
  }
  return uniql;  
}  
console.log(unique_char("thequickbrownfoxjumpsoverthelazydog"));

Sample Output:

thequickbrownfxjmpsvlazydg

Flowchart:

Live Demo:

See the Pen JavaScript - Extract unique characters from a string-function-ex- 16 by w3resource (@w3resource) on CodePen.

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Previous: Write a JavaScript function to compute the value of bn where n is the exponent and b is the bases.
Next: Write a JavaScript function to get the number of occurrences of each letter in specified string.

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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