JAVASCRIPT

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.

string concatenation in js

var str1 = "Hello ";
var str2 = "world!";
var res = str1.concat(str2);
console.log(res);

how to concatenate strings and variables in javascript

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

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

js concat string

const str1 = 'Hello';
const str2 = 'World';

console.log(str1.concat(' ', str2));
// expected output: "Hello World"

console.log(str2.concat(', ', str1));
// expected output: "World, Hello"

concat js inside string

// using text literal
clssName={`d-block ${error ? "text-danger" : ""}`}

what concatenation in javascript

/*
Note:

Concatenation in javascript
Concat() The concat() method is used to merge two or more arrays. 
This method does not change the existing arrays but instead returns a new array.
Concatenation is when you add string to an integer then the integer becomes a string.
*/


//CODE//

var myAge = 100;
console.log("My age is" + myAge);
myAge = 29;
console.log("My age next year will be" + myAge);

how to concatenate a string in javascript

let first_string = 'I am a programmer, ';
let second_string = 'I am indisposable.';
let what_i_said  = first_string + second_string;
console.log(what_i_said);

/* OR 
*/

let tell_my_boss = first_string.concat(second_string);
console.log(tell_my_boss);

how to concatenate in javscript

var one = 'Hello';
var two = 'World';

console.log(one + two);
It will print: HelloWorld

console.log(one + ' ' + two);
It will print: Hello World

js concatenate strings

const str1 = 'Hello';
const str2 = 'World';

console.log(str1 + str2);
>> HelloWorld

console.log(str1 + ' ' + str2);
>> Hello World

string javascript concatenation

    var dest = new String("");
    var src = new String("aze");
    var ar = new Array();
    ...
    ar.push(src);
    ar.push(src);
    ...
    dest = ar.join("");

javascript concatenation

// the fastest way to string concat in cycle when number of string is less than 1e6
// see https://medium.com/@devchache/the-performance-of-javascript-string-concat-e52466ca2b3a
// see https://www.javaer101.com/en/article/2631962.html
function concat(arr) {
    let str = '';
    for (let i = 0; i < arr.length; i++) {
        str += arr[i];
    }

    return str;
}

string javascript concatenation

    var dest = new String("");
    var src = new String("aze");
    ...
    dest += src + src + src + src + src;

string concat in js

let string1 = "Hello"
let string2 = "World"

let finalString = string1 + ", " + string2 + "!" // Hello, World!