A summary of common techniques of JS interception and split string

In this paper, we describe the common methods of JS intercepting and splitting strings. Share to everyone for your reference, as follows:

JS intercept string can be used substring () or slice ()

Function: substring ()

Definition: substring (start,end) represents a string from start to end, including the character of the start position but excluding the end position.

Function: string interception, such as want to get "minidx" from "minidxsearchengine" will use SUBSTRING (0,6)

Example:

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123	varsrc="images/off_1.png";alert(src.substring(7,10));//弹出值为：off

Function: substr ()

Definition: substr (start,length), which starts from the start position, intercepts a string of length lengths.

Function: String intercept

Example:

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123	varsrc="images/off_1.png";alert(src.substr(7,3));//弹出值为：off

Function: Split ()

Function: Use a specified delimiter to store a string into an array

Example:

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123	str="jpg|bmp|gif|ico|png";arr=theString.split("|");//arr是一个包含字符值"jpg"、"bmp"、"gif"、"ico"和"png"的数组

Function: John ()

Function: Merges an array into a string using the delimiter of your choice

Example:

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1234	var delimitedstring=myarray.join (delimiter); var mylist= new array ( "BMP" "GIF" "ico" "PNG" var portablelist=mylist.join ( "|" //result is jpg|bmp|gif|ico|png

Function: IndexOf ()

Function: Returns the subscript of the first character of a matched substring in a string

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var mystring= "JavaScript" var w=mystring.indexof ( var x=mystring.indexof ( " S " ) x would be 4 var y=mystring.indexof ( var z=mystring.indexof ( "key"

Function: LastIndexOf ()

Definition: The LastIndexOf () method returns the first character index value of a character or string that appears right-to-left (as opposed to indexof)

Function: Returns the string index value

Example:

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1234	varsrc="images/off_1.png";alert(src.lastIndexOf(‘/‘));alert(src.lastIndexOf(‘g‘));//弹出值依次为：6,15

Supplement: Differences between the substr and substring methods

Substr method

Returns a substring of the specified length starting at the specified position.

Stringvar.substr (start [, length])

Parameters

Stringvar

Required option. The string literal or string object to extract the substring from.

Start

Required option. The starting position of the desired substring. The index of the first character in the string is 0.

Length

Options are available. 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 argument is not specified, the substring continues to the end of the stringvar.

Example

The following example demonstrates the use of the Substr method.

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function substrdemo () {    var Code class= "JS plain" >s, ss;        //declare variables.    var s = "The rain in Spain falls mainly in the plain."    SS = s.substr (5); //gets the substring.    return (ss);        //return "Spain". }

Substring method

Returns a substring at the specified position in a string object.

Strvariable.substring (start, end)
"String Literal". Substring (start, end)

Parameters

Start

Indicates the starting position of the substring, starting at 0.

End

Indicates the ending position of the substring, starting at 0.

Description

The substring method returns a string containing a substring from start to last (without end).

The substring method uses the smaller values from start and end as the starting point for the substring. For example, strvar.substring (0, 3) and strvar.substring (3, 0) will return the same substring.

If start or end is NaN or negative, replace it with 0.

The length of the substring equals the absolute value of the difference between start and end. For example, the length of the substring returned in strvar.substring (0, 3) and strvar.substring (3, 0) is 3.

Example

The following example demonstrates the use of the substring method.

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functionSubstringDemo(){  var ss; // 声明变量。  vars = "The rain in Spain falls mainly in the plain..";  ss = s.substring(12, 17); // 取子字符串。  return(ss); // 返回子字符串。}

A summary of common techniques of JS interception and split string