Example of js charAt usage

Source: Internet
Author: User

Eg:
Copy codeThe Code is as follows:
<Html>
<Body>

<Script type = "text/javascript">

Var str = "Hello world! "
Document. write ("The first character is:" + str. charAt (0) + "<br/> ")
Document. write ("The second character is:" + str. charAt (1) + "<br/> ")
Document. write ("The third character is:" + str. charAt (2 ))

</Script>

</Body>
</Html>

Result:

The first character is: H
The second character is: e
The third character is: l

Definition and usage

The charAt () method returns characters at a specified position.

Note that JavaScript does not have a character data type different from the string type, so the returned character is a string with a length of 1.

Syntax

StringObject. charAt (index)

Parameter description

Index is required. Represents the number at a certain position in the string, that is, the subscript of the character in the string.

Tips and comments

Note: The subscript of the first character in the string is 0. If the index parameter is not between 0 and string. length, this method returns an empty string.

Instance

In the string "Hello world! ", We will return the character at location 1:
Copy codeThe Code is as follows:
<Script type = "text/javascript">

Var str = "Hello world! "
Document. write (str. charAt (1 ))

</Script>

The output of the above Code is:

E

Returns the characters at the specified index position.

StrObj. charAt (index)

Parameters

StrObj

Required. Any String object or text.

Index

Required. Returns the zero-based index of the expected characters. The valid value is the value between 0 and the string length minus 1.

Description

The charAt method returns a character value at the specified index position. The index of the first character in the string is 0, the index of the second character is 1, and so on. If the index value exceeds the valid range, an empty string is returned.

Example

The following example illustrates the usage of the charAt method:
Copy codeThe Code is as follows:
Function charAtTest (n ){
Var str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; // initialize the variable.
Var s; // name variable.
S = str. charAt (n-1); // from the position where the index is n-1
// Obtain the correct characters.
Return (s); // The return character.
}

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