How can I add a variable to console.log?

Question

I'm making a simple game in JavaScript but in the story I need it to say the players name. so what I have so far is:

var name = prompt("what is your name?");

console.log("story" name "story);

how do I do the second line? or there is another way I could do this. Is it possible to have 2 console.log(); on 1 line in the console?

Are you just looking to concatenate strings together? What do you mean by "do the second line"? — cogsmos, May 17 '13 at 03:46
^ cogsmos, it doesn't matter now, my question has been answered — Bradley McInerney, May 17 '13 at 06:00
Glad you figured it out. In JavaScript the + can be used for arithmetic and also for joining two strings together (also called concatenation). Take a look here for some more details: http://www.w3schools.com/js/js_operators.asp — cogsmos, May 17 '13 at 06:09

score 126 · Accepted Answer · edited Sep 12 '19 at 09:29

126

Then use + to combine strings:

console.log("story " + name + " story");

edited Sep 12 '19 at 09:29

Gianfranco P.

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answered May 17 '13 at 03:28

Joseph

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Sanjib Debnath · Answer 2 · 2020-04-20T19:01:47.753

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You can use another console method:

let name = prompt("what is your name?");
console.log(`story ${name} story`);

edited Apr 20 '20 at 19:01

answered Jul 26 '16 at 05:56

Sanjib Debnath

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Template strings are awesome. But provided someone uses ES6. Since in the example "var" is used (could be ES6 ofcourse) but don't think we can assume that here... – therebelcoder May 15 '17 at 12:27

Coin_op · Answer 3 · 2013-05-17T21:02:30.010

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console.log takes multiple arguments, so just use:

console.log("story", name, "story");

If name is an object or an array then using multiple arguments is better than concatenation. If you concatenate an object or array into a string you simply log the type rather than the content of the variable.

But if name is just a primitive type then multiple arguments works the same as concatenation.

edited May 17 '13 at 21:02

answered May 17 '13 at 03:29

Coin_op

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or also `console.log('story %s story',name);` – Muhammad Umer Jul 14 '14 at 03:33
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Minor thing, but if you're in a less conventional setting like Parse's Cloud Code sending an array or using %s doesn't work.. so you're forced to concatenate. – Derek Lucas Jul 18 '14 at 19:48
That's great @MuhammadUmer, I thought that was only a Python thing. In Python `%s` is the best method for concatenating strings, since you don't need to change the variable type first. I wonder if it's the same in JS? – JasTonAChair Sep 22 '15 at 09:40

score 66 · Answer 4 · answered Jun 14 '17 at 12:09

66

There are several ways of consoling out the variable within a string.

Method 1 :

console.log("story", name, "story");

Benefit : if name is a JSON object, it will not be printed as "story" [object Object] "story"

Method 2 :

console.log("story " + name + " story");

Method 3: When using ES6 as mentioned above

console.log(`story ${name} story`);

Benefit: No need of extra , or +

Method 4:

console.log('story %s story',name);

Benefit: the string becomes more readable.

answered Jun 14 '17 at 12:09

mannutech

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@egemen what does freemarker have to do with it? It's an ECMAscript 2015 template literal – Nico Van Belle May 14 '19 at 06:39
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This is the best answer. – Stephen Collins Jan 22 '20 at 18:37

score 23 · Answer 5 · edited Mar 23 '17 at 15:07

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When using ES6 you can also do this:

var name = prompt("what is your name?");
console.log(`story ${name} story`);

Note: You need to use backticks `` instead of "" or '' to do it like this.

edited Mar 23 '17 at 15:07

Mikaël Mayer

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answered Mar 23 '17 at 14:33

EinArzt

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score 6 · Answer 6 · answered May 17 '13 at 03:29

6

You can pass multiple args to log:

console.log("story", name, "story");

answered May 17 '13 at 03:29

Lyn Headley

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score 4 · Answer 7 · answered Sep 12 '19 at 09:29

%j works for only Node.js. %j converts a value to a JSON string and inserts it.

console.log('%j new messages for', 7, 'john')
// 7 new messages for john

More string substitutions here:

https://exploringjs.com/impatient-js/ch_console.html

Docs:

hmit · Answer 8 · 2015-02-01T06:39:10.597

It depends on what you want.

console.log("story "+name+" story") will concatenate the strings together and print that. For me, I use this because it is easier to see what is going on.

Using console.log("story",name,"story") is similar to concatenation however, it seems to run something like this:

 var text = ["story", name, "story"];
 console.log(text.join(" "));

This is pushing all of the items in the array together, separated by a space: .join(" ")

score 1 · Answer 9 · edited Jan 25 '17 at 12:42

1

Both console.log("story" + name + "story") and console.log("story", name, "story") works just fine as mentioned in earlier answers.

I will still suggest of having a habit of console.log("story", name, "story"), because, if trying to print the object contents, like json object, having "story" + objectVariable + "story" will convert it into string.

This will have output like : "story" [object Object] "story".

Just a good practice.

edited Jan 25 '17 at 12:42

Grey

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answered Jan 25 '17 at 12:09

Sagar Kulkarni

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Then why are you suggesting "," one. As it will just print [object object]. Mostly, we want string version which will get frmo "+". Right? – Satish Patro Mar 30 '19 at 04:13

score 0 · Answer 10 · edited Nov 12 '18 at 21:45

0

You can also use printf style of formatting arguments. It is available in at least Chrome, Firefox/Firebug and node.js.

var name = prompt("what is your name?");

console.log("story %s story", name);

It also supports %d for formatting numbers

edited Nov 12 '18 at 21:45

jmartori

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answered Nov 01 '18 at 21:16

Ben Anderson

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score -4 · Answer 11 · answered May 17 '18 at 08:59

-4

You can use the backslash to include both the story and the players name in one line.

var name=prompt("what is your name?"); console.log("story"\name\"story");

answered May 17 '18 at 08:59

kimxons

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How can I add a variable to console.log?

11 Answers11

More string substitutions here:

Docs:

Linked