Developed By
Gautam Kumar - Full stack developer
DEEP DIVE INTO
The charCodeAt()
method in JavaScript is used to retrieve the Unicode value (UTF-16 code unit) of a character at a specified index in a string. This method allows you to obtain the numeric representation of a character, which is especially useful when working with text processing, encoding, or comparing characters.
javascriptstring.charCodeAt(index)
string: The string from which you want to extract the character code.
index: The index of the character for which you want to retrieve the Unicode value.
Here's a deep dive into the charCodeAt()
method:
javascriptconst text = "Hello";
const charCode = text.charCodeAt(1);
console.log(charCode); // 101
In this example, the character at index 1 in the string "Hello" is "e," and its Unicode value is 101, which is retrieved using the charCodeAt()
method.
The charCodeAt()
method works for all characters, including special characters and non-Latin characters. It returns the Unicode value for the character at the specified index.
javascriptconst specialChar = "€"; // Euro symbol
const charCode = specialChar.charCodeAt(0);
console.log(charCode); // 8364
The charCodeAt()
method is designed to work with string values. If you pass a non-string value as the index, it will be coerced into a string and then treated as an index:
javascriptconst text = "Hello";
const index = 2;
const charCode = text.charCodeAt(index.toString());
console.log(charCode); // 108
If you provide an out-of-bounds index, the charCodeAt() method will return NaN (Not-a-Number):
javascriptconst text = "Hello";
const charCode = text.charCodeAt(10);
console.log(charCode); // NaN
JavaScript uses UTF-16 encoding, which means that characters within the Basic Multilingual Plane (BMP) can be represented by a single 16-bit code unit. Characters outside the BMP (e.g., emoji, certain Asian characters) are represented by surrogate pairs, requiring two code units to represent a single character. In such cases, charCodeAt() returns the code unit of the high surrogate.
If you have a character code and want to convert it back to the corresponding character, you can use the String.fromCharCode()
method:
javascriptconst charCode = 101; // Unicode value for "e"
const character = String.fromCharCode(charCode);
console.log(character); // "e"
The charCodeAt()
method is a powerful tool when working with text and character encoding, allowing you to access the numeric representation of characters within a string. It is often used when dealing with text processing, internationalization, or comparing characters in JavaScript applications.