Manipulating functions and methods of strings in JavaScript

1. String conversion toString (): You can convert any type of data to a string

var num= 19; 19

var mystr = num.tostring (); "19"

var mystr = String (num); "19"

var mystr = "" + num; "19

2, String split split (","): divides the string into bits multiple strings, split () the second parameter, which represents the maximum length of the returned string array

var str = "I,love,you,do,you,love,me"

var  strArr = myStr .split( "," ); // ["I", "Love", "You", "Do", "you", "love", "me"]; var strLim = myStr .split( "," , 3); // ["I", "Love", "You"];3. String cuttingSlice (i,j), substring (i,j)The truncated character should be in the second argument before a "i,j" var str = "I,love,you,do,you,love,me" var slice = str.slice (1,5); ", Lov" varsubstring= Str.substring (1,5); ", Lov" varsubstr= Str.substr (1,5); ", Love" substr (i,j) The second parameter represents " the maximum length of a truncated string " 4. Find the character at the given positioncharAt (8) var myStr = "I,love,you,Do,you,love,me" ; var theChar = myStr.charAt(8); // "o",同样从0开始5. Query substring Str.indexof ()

The first function:indexOf (), which starts from the beginning of the string, finds the corresponding coordinates, and cannot find the return-1. Following

var myStr =  "I,Love,you,Do,you,love,me" ; var index = myStr.indexOf( "you" );  // 7 ,基于0开始,找不到返回-1

The second function:lastIndexOf (), which starts at the end of the string and finds the corresponding coordinates returned, cannot find return-1. As follows:

var myStr =  "I,Love,you,Do,you,love,me" ; var index = myStr.lastIndexOf( "you" );  // 14  

Manipulating functions and methods of strings in JavaScript