string concat function javascript code example

Example 1: how to concatenate strings javascript

var str1 = "Hello ";
var str2 = "world!";
var res = str1.concat(str2);
// does not change the existing strings, but
// returns a new string containing the text
// of the joined strings.

Example 2: how to concatenate strings and variables in javascript

const helloName = name => `Hello ${name}!`

Example 3: string concat javascript

//This method adds two or more strings and returns a new single string.

let str1 = new String( "This is string one" ); 
let str2 = new String( "This is string two" ); 
let str3 = str1.concat(str2.toString());
console.log("str1 + str2 : "+str3)

output:
str1 + str2 : This is string oneThis is string two

Example 4: javascript string concat vs +

It is strongly recommended to use the string
concatenationoperators (+, +=) instead of String.concat
method for perfomance reasons