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JavaScript CharCodeAt

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ChartCodeAt()

The JavaScript CharCodeAt method is used to return the Unicode of the Character at specified index position. In this article we will show you, How to write ChartCodeAt() Function in JavaScript with example.

TIP: The index position in ChartCodeAt() Function will start from 0, Not 1.

JavaScript CharCodeAt Syntax

The basic syntax of the JavaScript CharCodeAt function is as shown below:

String_Object.CharCodeAt(Index_Position)
  • String_Object: Please select the valid String Object.
  • Index_Position: Please specify the index position of a desired character. If there is no character at specified index NaN is returned

Return Value

ChartCodeAt() Function returns the Unicode of the Character from String_Object at specified Index_Position. If we specify the Index position out of range then, ChartCodeAt() Function returns NaN.

JavaScript CharCodeAt Example

The following set of examples will help you understand the ChartCodeAt() Function in JavaScript Programming language.

JAVASCRIPT CODE

<!DOCTYPE html>
<html>
<head>
    <title> JavaScript CharCodeAt </title>
</head>
<body>
    <h1>JavaScript CharCodeAt </h1>
    <p id= "Content1">Content 1</p>
    <p id= "Content2">Content 3</p>
    <p id= "Content3">Content 2</p>
<script>
 var Str_Original = "Tutorial GateWay";
 var Str_Extracted = Str_Original.charCodeAt(9);
 var Str_Extracted1 = Str_Original.charCodeAt(Str_Original.length - 1);
 var Str_Extracted2 = Str_Original.charCodeAt(Str_Original.length);
    
 document.getElementById("Content1").innerHTML = "Charcter at Index position 9 = " + Str_Extracted;
 document.getElementById("Content2").innerHTML = "Charcter at Index position 15 = " + Str_Extracted1; 
 document.getElementById("Content3").innerHTML = "Charcter at Index position 16 = " + Str_Extracted2; 
</script>
</body>
</html>

OUTPUT

JavaScript CharCodeAt

ANALYSIS

Within the Script tag, First we declared the String variable and assigned a value using following statement

var Str_Original = "Tutorial GateWay";

Following statement will find the Character Unicode at index position 9, and it will be G.

var Str_Extracted = Str_Original.charCodeAt(9);

NOTE: You should count the space as One Character.

In the next line we are using the JavaScript len() function to calculate the string length.

var Str_Extracted1 = Str_Original.charCodeAt(Str_Original.length - 1);

From the above statement you can observe that, we are subtracting 1 from string length because, length of a Str_Original is 16 and we all know that, there is no character at index position 16. Let us see, what will happen when we select the index position as 16

var Str_Extracted2 = Str_Original.charAt(Str_Original.length);

From the below screenshot you can observe that, it is returning NaN.

Following statements will place the content in the respective paragraphs

document.getElementById("Content1").innerHTML = "Charcter at Index position 9 = " + Str_Extracted;
document.getElementById("Content2").innerHTML = "Charcter at Index position 15 = " + Str_Extracted1; 
document.getElementById("Content3").innerHTML = "Charcter at Index position 16 = " + Str_Extracted2;

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