js interception function (indexOf, join, etc.)_javascript skills

Function: indexOf()
Function: Return 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

Function: split()
Function: Use a specified delimiter to split a string and store it in an array

Copy code The code is as follows:

str="jpg|bmp|gif|ico|png";
arr=theString.split("|");
//arr is an array containing the character values ​​"jpg", "bmp", "gif", "ico" and "png"

Function: Join()
Function: Combine an array into a string using the delimiter of your choice var delimitedString=myArray.join(delimiter);

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: slice() and substring()
Both slice and substring can accept one or two parameters, the first parameter is to get the content to be intercepted The direct starting position of the string. If the second parameter is not empty, it is the previous digit of the end position of the string to be intercepted (that is, the end position obtained is not within the return value). If it is empty, it means that the entire The last character of the string.

Copy code The code is as follows:

Note: The number of digits in the string starts from 0