Some operations of string, such as arrays

1. String cutting

var a= "Hello World";//a.length=11
Alert (A.slice (3));
Alert (a.substring (3));
Alert (A.SUBSTR (3));//Three lo World

Alert (A.slice (3,7));//3 to 7
Alert (a.substring (3,7));//3~7
Alert (A.SUBSTR (3,7))//3 back 7 characters

Alert (A.slice ( -3));//a.length-3 begins, 11-3=8= "Rld";
Alert (a.substring ( -3));//substr will be regarded as 0,hello world;
Alert (A.SUBSTR (-3));//Same as slice mode

Alert (A.slice (3,-4));//(3,a.length (11-4=7)) Lo W
Alert (a.substring (3,-4)),//As (3,0), and its own adjustment to (0,3) characteristics, hel
Alert (A.SUBSTR (+3,-4));///also as (3,0), the following parameter is 0 nature is "" (empty string)

2 string IndexOf

var a= "Hello World";

A.indexof ("O");//4

A.lastindexof ("0");//7

A.indexof ("O", 6)//At the beginning of the 6th

A.lastindexof ("O", 6)

3.trim () Remove spaces

4.toLowerCase () case

toUpperCase ()

5. Find inside the string

1) match () is the same as RegExp

var a= "Hello World";
var b=/lo/;
var c=a.match (b);
Console.log (C[0],c.index,c.lastindex);

2) Search () returns only the first position, like C.index

var a= "Hello World";
var b=/lo/;
var c=a.search (b);
Console.log (C[0],c.index,c.lastindex);//Three undefined
Console.log (c);

Easy replacement of 6 strings

var a= "Cat,bat,fat,dat";
var b=a.replace (/at/g, "fuck");
Console.log (b);

The second parameter can also be encoded with a segment to update the matching results

var a= "Cat,bat,fat,dat";
var b=a.replace (/(. at)/g, "Fuck ($)");

It can also be a functional function (Match,pos,originaltext) is a pattern match, match the position of the string, the original character (the previous match)

var a= "<000<0.00<>0<.0";
var b=a.replace (/[<>.] /g,function (Match,pos,originaltext) {
Switch (match) {
Case "<":
Case ">":
return "1";
Case ".":
return originaltext;//<>. These
}
});
Console.log (b);

7 Serializing arrays

var a= "Sdds,sf,we,zc";
var b=a.split (",");
var c=a.split (/[/,]/);
Console.log (B,C);

8 Comparison of strings

var a= "Fuck";
var b= "E";
Console.log (A.localecompare (b));//cannot be directly reduced

9 fromCharCode () method

String.fromCharCode (104,101,108,108,111)); encoding converts to character hello

Some operations of string, such as arrays