String Method Summary

One, character method

charAt: Returns the character at the specified position.

var str= "ABCDEFG";//undefinedstr[0]//"a" because IE67 does not support this notation Str.charat (0)//"a"

charCodeAt: Returns the Unicode encoding of the character at the specified position.

Second, the string operation method, does not affect the original string, returns the new string

concat: string concatenation--Returns a new string without affecting the original string. More time with "+"

Slice: Extracts a fragment of a string that returns the extracted part. When the argument is negative, the passed negative value is added to the length of the string

substring: Extracts the characters between two specified index numbers in a string. All negative arguments are converted to 0

substr: Extracts the specified number of characters from the starting index number in the string. The negative first argument is prefixed with the length of the string, and the second argument of the negative is converted to 0

var str= "ABCDEFG"//undefinedstr.slice (0,1)//"A" str.substr (0,1)//"A" str//"ABCDEFG" Str.slice ( -3)//"EFG" Str.substring ( -3)//"ABCDEFG" Str.substr ( -3)//"EFG" Str.slice (3,-4)//"Str.slice (0,-4)//" ABC "str.substring (3,-4)/ /"ABC" STR.SUBSTR (3,-4)//""

Trim: Returns a new string after a trailing space has been deleted

trimleft: Remove opening spaces

trimright: Remove trailing spaces

var str= "abc"  //undefinedstr//"abc"  Str.trim ()//"abc" str//"   ABC  " Str.trimleft ()//"ABC  "

Case conversion:

toLowerCase

Tolocallowercase

toUpperCase

tolocaluppercase: A region-specific approach

Three, the string position method

indexOf: Returns the position of the first occurrence of a specified string value in a string.

lastIndexOf: Returns the position in a string at the specified position from the back to the forward search.

Str.indexof (' B ')//1str.lastindexof (' B ')//1

String Method Summary