JavaScript String codePointAt() Method
The JavaScript String codePointAt() method returns a non-negative integer value that represents the Unicode point of the character in the string starting at the specified index. If the given index is not within the range of 0 to str.length-1, the method returns "undefined" as a result.
This method returns the Unicode point value for both string characters and icons (emojis, symbols, etc.).
Syntax
Following is the syntax of JavaScript String codePointAt() method −
codePointAt(index)
Parameters
This method accepts a parameter named 'index', which is described below −
- index − The zero-based index(position) of the character is to be returned.
Return value
This method returns a non-negative integer representing the uni code point value of the character at the given index.
Example 1
Retrieve the Unicode point of the first character in the string by passing the index value as 0.
In the following example, we are using the JavaScript String codePointAt() method to retrieve the Uni code point value of the character in the given string "Tutorials Point" at the specified index 0.
<html>
<head>
<title>JavaScript String codePointAt() Method</title>
</head>
<body>
<script>
const str = "Tutorials Point";
document.write("String: ", str);
const index = 0;
document.write("<br>Index: ", index);
document.write("<br>The Uni code point value of the first character '", str.at(index), "' is: ", str.codePointAt(index));
</script>
</body>
</html>
Output
The above program returns the Uni code point value as 84 of the first character 'T' of the string "Tutorials Point".
String: Tutorials Point Index: 0 The Uni code point value of the first character 'T' is: 84
Example 2
Retrieve the Unicode point of the last character in the string.
The following is another example of the JavaScript String codePointAt() method. We use this method to retrieve the Uni code point of character in the given string "Hello World" at the specified index str.length-1, which is the last element.
<html>
<head>
<title>JavaScript String codePointAt() Method</title>
</head>
<body>
<script>
const str = "Hello World";
document.write("String: ", str);
const index = str.length-1;
document.write("<br>Index: ", index);
document.write("<br>The Uni code point value of the last character '", str.at(-1), "' is: ", str.codePointAt(index));
</script>
</body>
</html>
Output
After executing the above program, it will return uni code value of character 'd' as 100.
String: Hello World Index: 10 The Uni code point value of the last character 'd' is: 100
Example 3
If the index parameter value is not in the range of 0 to str.length-1, it will return undefined.
In this example, we use the JavaScript String codePointAt() method to retrieve a uni code point of a character in the string "JavaScript" at the specified index -3, which is out of the range of 0 - str.length-1.
<html>
<head>
<title>JavaScript String codePointAt() Method</title>
</head>
<body>
<script>
const str = "JavaScript";
document.write("String: ", str);
const index = -3;
document.write("<br>Index: ", index);
document.write("<br>The Uni code point value of character the specified index ", index, " is: ", str.codePointAt(index));
</script>
</body>
</html>
Output
Once the above program is executed, it will return "undefined".
String: JavaScript Index: -3 The Uni code point value of character the specified index -3 is: undefined
Example 4
The Unicode code point value of icons (emojis).
In this program, the codePointAt() method is used to retrieve the Unicode point value of the icons.
<html>
<head>
<title>JavaScript String codePointAt() Method</title>
</head>
<body>
<script>
document.write("Character(icon): ", "😀", ", Uni code point: ", "😀".codePointAt(0));
</script>
</body>
</html>
Output
The above program returns the Uni code point of the icon "😀" as "128512" −
Character(icon): 😀, Uni code point: 128512
Example 5
In the given program, we are using the codePointAt() method within the for-loop to retrieve the uni code point of all the characters present in the string "Welcome to Tutorials Point".
<html>
<head>
<title>JavaScript String codePointAt() Method</title>
</head>
<body>
<script>
const str = "Welcome to Tutorials Point";
document.write("String: ", str);
document.write("<br>Uni code point value of all characters:<br>")
for(let i = 0; i<str.length; i++){
document.write("Character: ", str.at(i), ", Uni code point: ", str.charCodeAt(i), "<br>");
}
</script>
</body>
</html>
Output
The above programs returns the uni code point of all characters:
String: Welcome to Tutorials Point Uni code point value of all characters: Character: W, Uni code point: 87 Character: e, Uni code point: 101 Character: l, Uni code point: 108 Character: c, Uni code point: 99 Character: o, Uni code point: 111 Character: m, Uni code point: 109 Character: e, Uni code point: 101 Character: , Uni code point: 32 Character: t, Uni code point: 116 Character: o, Uni code point: 111 Character: , Uni code point: 32 Character: T, Uni code point: 84 Character: u, Uni code point: 117 Character: t, Uni code point: 116 Character: o, Uni code point: 111 Character: r, Uni code point: 114 Character: i, Uni code point: 105 Character: a, Uni code point: 97 Character: l, Uni code point: 108 Character: s, Uni code point: 115 Character: , Uni code point: 32 Character: P, Uni code point: 80 Character: o, Uni code point: 111 Character: i, Uni code point: 105 Character: n, Uni code point: 110 Character: t, Uni code point: 116