Detailed summary of common methods for intercepting strings in JS_javascript skills

Use substring() or slice()

Function: split()
Function: Use a specified delimiter to split and store a string into an array
Example:
str=”jpg|bmp|gif|ico|png”;
arr=theString.split(”|”);
//arr is an array containing the character values ​​"jpg", "bmp", "gif", "ico" and "png"

Function: John()
Function: Combine an array into a string using a delimiter of your choice
Example:

Copy code The code is as follows:

var delimitedString=myArray.join(delimiter);
var myList=new Array("jpg","bmp","gif","ico","png");
var portableList=myList.join(”|”);
//The result is jpg|bmp|gif|ico|png

Function: substring()
Function: String interception. For example, if you want to get "Minidx" from "MinidxSearchEngine", you need to use substring(0,6)

Function: indexOf()
Function: Returns the subscript of the first character matching the substring in the string

Copy code The code is as follows:

var myString=”JavaScript”;
var w=myString.indexOf(”v”);w will be 2
var x=myString.indexOf(”S”);x will be 4
var y=myString.indexOf(”Script”);y will also be 4

var z=myString.indexOf(”key”);z will be -1

Continued:

1.substring method

Definition and usage
The substring method is used to extract characters between two specified subscripts in a string.

Grammar
stringObject.substring(start,stop)

Parameter Description
start is required. A nonnegative integer that specifies the position in stringObject of the first character of the substring to be extracted.
stop is optional. A nonnegative integer that is one position in the stringObject that is one more than the last character of the substring to be extracted. If this parameter is omitted, the returned substring will go to the end of the string.

Return value
A new string value containing a substring of stringObject containing all the characters from start to stop-1 and having a length of stop minus start.

Description
The substring returned by the substring method includes the characters at start but not the characters at end.
If start and end are equal, then this method returns an empty string (that is, a string of length 0).
If start is greater than end, the method swaps the two parameters before extracting the substring.
If start or end is negative, it is replaced by 0.

2.substr method

Definition and usage
The substr method is used to return a substring of a specified length starting at a specified position.

Grammar
stringObject.substr(start [, length ])

Parameter Description
start is required. The starting position of the desired substring. The first character in the string has index 0.
length is optional. The number of characters that should be included in the returned substring.

Description
If length is 0 or negative, an empty string is returned.
If this parameter is not specified, the substring will be continued to the end of stringObject.

Example:

Copy code The code is as follows:

var str = "0123456789";

alert(str.substring(0));------------"0123456789"
alert(str.substring(5));------------"56789"
alert(str.substring(10));-----------""
alert(str.substring(12));-----------""
alert(str.substring(-5));-----------"0123456789"
alert(str.substring(-10));----------"0123456789"
alert(str.substring(-12));----------"0123456789"
alert(str.substring(0,5));----------"01234"
alert(str.substring(0,10));---------"0123456789"
alert(str.substring(0,12));---------"0123456789"
alert(str.substring(2,0));----------"01"
alert(str.substring(2,2));----------""
alert(str.substring(2,5));----------"234"
alert(str.substring(2,12));---------"23456789"
alert(str.substring(2,-2));---------"01"
alert(str.substring(-1,5));---------"01234"
alert(str.substring(-1,-5));--------""

alert(str.substr(0));---------------"0123456789"
alert(str.substr(5));---------------"56789"
alert(str.substr(10));--------------""
alert(str.substr(12));--------------""
alert(str.substr(-5));--------------"0123456789"
alert(str.substr(-10));-------------"0123456789"
alert(str.substr(-12));-------------"0123456789"
alert(str.substr(0,5));-------------"01234"
alert(str.substr(0,10));------------"0123456789"
alert(str.substr(0,12));------------"0123456789"
alert(str.substr(2,0));-------------""
alert(str.substr(2,2));-------------"23"
alert(str.substr(2,5));-------------"23456"
alert(str.substr(2,12));------------"23456789"
alert(str.substr(2,-2));------------""
alert(str.substr(-1,5));------------"01234"
alert(str.substr(-1,-5));-----------""