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Native method of JavaScript manipulation Strings _ Basics

Source: Internet
Author: User
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Join ([separator]) array elements are grouped into strings

ToString () represents an array as a string

Reverse () array inversion--change the original array itself

ValueOf () returns an array value

Copy Code code as follows:

<script type= "Text/javascript" >
var fruits= ["Apple", "pear", "orange"];//recommend this to define, initialize an array
With (document) {
Writeln ("<ul>");
Writeln ("<li>" +fruits.join () + "</li>");
Writeln ("<li>" +fruits.join ("--") + "</li>");
Writeln ("<li>" +fruits.reverse (). Join () + "</li>");
Writeln ("<li>" +fruits.valueof () + "</li>");
Writeln ("</ul>");
}
</script>

toUpperCase ()--capitalization

CharAt (Index)--refers to a character

SUBSTRING (begin,len)--Truncate string

Copy Code code as follows:

<script type= "Text/javascript" >
var str= "JavaScript";
var num=1234;
With (document) {
Writeln (Str.touppercase () + "<br>");
Writeln (Num.tostring (). CharAt (3) + "<br>");
Writeln (str.substring (0,4) + "<br>");
}
</script>

Run Result:

Copy Code code as follows:

Javascript
3
Java

indexof--determine if a character exists in the string

Copy Code code as follows:

<script type= "Text/javascript" >
function Isemail () {
var emailvalue=document.getelementsbyname ("email") [0].value;
if (Emailvalue.indexof ("@") ==-1) {
Alert ("Please enter the correct email");
}else{
Alert ("OK");
}
}
</script>
<body>
<input type= "text" name= "email" >
<input type= "button" value= "Check" onclick= "Isemail ();" >
</body>

The small partners are aware of the native methods of manipulating strings in JavaScript, and many times these native methods can simply implement the functionality we need.

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