JavaScript Learning Tutorial: string concatenation

Article Introduction: JS Built-in features one: string concatenation.

JS built-in features one: string connection;

If the plus (+) operator is used for numbers, the addition of two numbers is added;

However, by acting on a string, it means that the string is connected and the second string is concatenated after the first.

var a = "Hello,"; var B = "World";

var s = a + B; Generate string "Hello,world";

alert (s);//Display a string

alert (s.length);//The length of the display string

String other method of invocation:

S.charat (0); First character: "H"

S.charat (s.length-1); Last string "D"

S.substring (1,4); 2nd to 4th string Note is not the 2nd to 5th string "ell";

S.slice (1,4); Ditto "ell";

S.replace ("H", "H"); "H" replaces "H", full character replacement,

S.touppercase (); Full-text capitalization

S.slice (-3); The last three characters "Rld";

S.indexof ("L"); The position of the first appearance of the character L; "2"

S.lastindexof ("L"); Position of the last occurrence of the character L; "10"

S.indexof ("L", 3); The first occurrence of the string at position 33 and after "3"

S.split (","); ["Hello", "World"] split into substrings

Note: string can not be subtracted, can only intercept part of the string addition "+";