JavaScript charCodeAt() method
JavaScript charCodeAt() Method
Instance
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<p id="demo">单击按钮显示字符串的第一个字符的编码。</p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction(){
var str="HELLO WORLD";
var n=str.charCodeAt(0);
document.getElementById("demo").innerHTML=n;
}
</script>
</body>Run Example»
Click the "Run Example" button to view the online example
Definition and usage
The charCodeAt() method can return the Unicode encoding of the character at the specified position.
The position of the first character in the string is 0, the position of the second character is 1, and so on.
Browser support
All major browsers support the charCodeAt() method
Syntax
string.charCodeAt(index)
Parameter value
| Parameter | Description |
|---|---|
| index | Required. A number that represents a certain position in a string, that is, the subscript of a character in the string. |
Return value
| Type | Description |
|---|---|
| Number | Returns the Unicode encoding of the character at the specified position. |
Technical Details
| JavaScript Version: | 1.2 |
|---|
More examples
Instances
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<p id="demo">单击按钮显示字符串最后一个字符的UNICODE 编码</p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction(){
var str="HELLO WORLD";
var n=str.charCodeAt(str.length-1);
document.getElementById("demo").innerHTML=n;
}
</script>
</body>Running examples»
Click the "Run Instance" button to view the online instance
