JavaScript | String.prototype.charCodeAt()

str.charCodeAt() function returns a Unicode character set code unit of the character present at the index in the string specified as the argument. The syntax of the function is as follows:

str.charCodeAt(index)

Arguments
The only argument to this function is the index of the character in the string whose Unicode is to be used. The range of the index is from 0 to length – 1.

Return value
This function returns the Unicode (ranging between 0 and 65535) of the character whose index is provided to the function as the argument. If the index provided is out of range the this function returns NaN.

Examples for the above function are provided below:

Example 1:

Input:
var str = 'ephemeral';
print(str.charCodeAt(4));

Output:
109

In this example the function charCodeAt() extracts the character from the string at index 4. Since this character is m, therefore this function returns the Unicode sequence as 109.

Example 2:

Input:
var str = 'ephemeral';
print(str.charCodeAt(20));

Output:
NaN

In this example the function charCodeAt() extracts the character from the string at index 20. Since the index is out of bounds for the string, therefore this function returns the answer as NaN.

Codes for the above function are provided below:

Program 1:

<script> 
// JavaScript to illustrate charCodeAt() function 
  
function func() { 
    var str = 'ephemeral'; 
  
    // Finding the code of the character at 
    // given index  
    var value = str.charCodeAt(4); 
    document.write(value);     
} 
  
func(); 
</script> 

Output:

Program 2:

<script> 
// JavaScript to illustrate charCodeAt() function 
  
function func() { 
    var str = 'ephemeral'; 
  
    // Finding the code of the character  
    // at given index  
    var value = str.charCodeAt(20); 
  
    document.write(value);     
} 
func(); 
</script>  

Output:

NaN

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