how to concat string with dynamic value if that value exists

Question

Suppose I have a variable data:

var data = 6;

If we have data value and it's greater than 5 then the output should be:

"Hello x, 6 is your promo code"

If we don't have a data value, or the value is less than 5 then the output should be:

"Hello x"

How can I do this with a single line of JavaScript?

if (data >= 6) return "Hello x, 6 is your promo code"; else return "Hello x" — Webster, Sep 21 '16 at 07:06
Possible duplicate of [Javascript if else shorthand](http://stackoverflow.com/questions/11069278/javascript-if-else-shorthand) — Undeadparade, Sep 21 '16 at 07:08
I am feel ironic, it's impossible you can't solve this simple problem since your reputation is high enough.. — Fadhly Permata, Sep 21 '16 at 07:12

score 3 · Accepted Answer · answered Sep 21 '16 at 07:08

3

Try this:

var numb = 12;
var msg = "Hello x" + (numb > 5 ? (', ' + numb + ' is your promo code') : '');
console.log(msg);

answered Sep 21 '16 at 07:08

Fadhly Permata

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score 3 · Answer 2 · answered Sep 21 '16 at 07:09

3

document.write(data > 5? "Hello x, 6 is your promo code" : "Hello x");

answered Sep 21 '16 at 07:09

halim

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score 2 · Answer 3 · answered Sep 21 '16 at 07:07

You could use a conditional (ternary) operator

condition ? expr1 : expr2

The conditional (ternary) operator is the only JavaScript operator that takes three operands. This operator is frequently used as a shortcut for the if statement.

var data = 6,
    promo = data > 5 ? "Hello x, 6 is your promo code" : 'Hello x';

console.log(promo);

score 1 · Answer 4 · answered Sep 21 '16 at 07:08

1

try this:

(data>5) ? "Hello x," +6+" is your promo code" : "Hello x

answered Sep 21 '16 at 07:08

Bartłomiej Gładys

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score 1 · Answer 5 · answered Sep 21 '16 at 07:08

1

    var x=3;
    alert('Hello' + ((typeof(x) =='undefined' || x<5) ? ' x, ' : ', ' +x + ' is your promo code'));

answered Sep 21 '16 at 07:08

salih0vicX

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var x=32; alert('Hello' + ((typeof(x) =='undefined' || x<5) ? ' x, ' : ', your promo code is '+x)); It also ensures that variable x is declared ... If it is not declared, the result would be 'Hello x, ' – salih0vicX Sep 21 '16 at 07:24

score 1 · Answer 6 · answered Sep 21 '16 at 07:12

1

I will say, it's a simple ternary operator

var data = 6,
    minVal = 5;

var promo = data > minVal ? "Hello x, " + data + " is your promo code" : 'Hello x';

console.log(promo);

answered Sep 21 '16 at 07:12

Jose Paredes

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score 0 · Answer 7 · answered Jul 28 '22 at 07:14

0

I like to use the Template literals syntax

For example: `${data > 5 ? "Hello x, 6 is your promo code" : "Hello x"}``

answered Jul 28 '22 at 07:14

Ar26

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Alexander Sasha Shcherbakov · Answer 8 · 2022-12-01T08:46:26.827

There's a magic way with JS that kinda breaks your brain but it works

var numValue = 6
var finalValue = `Hello X${numValue > 5 && `, ${numValue} is your promo code` || ''}`

console.log(finalValue)
// Hello X, 6 is your promo code

Where if the numValue=5

const numValue = 5
const finalValue = `Hello X${numValue > 5 && `, ${numValue} is your promo code` || ''}`

console.log(finalValue)
// Hello X

So in case numValue > 5 is true the returned value be ${numValue} is your promo code but if it's false then we need to add the || '' to return an empty string or you will have false in your string.

It's not a clean solution but it's a solution to consider

But for your own benefit and others when reading the code the conventional ways are better

Example:

const n = 6
let fv = "Hello X"

fv += n > 5 ? `, ${n} is your promo code` : ''

console.log(fv)
// Hello X, 6 is your promo code

Or the other ways suggested above altho some of those examples look like an overkill

GLHF :)

how to concat string with dynamic value if that value exists

8 Answers8