How to incorporate a boolean value in a string in JavaScript

Question

Suppose I want to incorporate a boolean value in some string I print out, like

var x=1;
var y=2;
document.write("<p>The result is "+x==y+"</p>");

Normally, this does not give me the requred output. Is there a method to directly print boolean expressions in the document.write() itself? I do not want to use if-else and then assign separate values to variables and then print them. PS - I have just started learning JavaScript.

Do you want to output true or false?

VisioN
– VisioN

2013-12-19 17:56:34 +00:00
Commented Dec 19, 2013 at 17:56 — VisioN
– VisioN, Commented Dec 19, 2013 at 17:56

Dave Newton · Accepted Answer · 2013-12-19 17:58:34Z

6

Put parentheses around the boolean expression:

document.write("<p>The result is " + (x == y) + "</p>");

If you don't, you're doing this:

document.write(("<p>The result is " + x) == (y + "</p>"));

And in general, don't use document.write.

answered Dec 19, 2013 at 17:58

Dave Newton

161k27 gold badges263 silver badges310 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

nsane Over a year ago

What do I use then? I'm relatively new to JavaScript and so far the tutorials at W3Schools have used document.write. Are there any loopholes with it?

Dave Newton Over a year ago

@nisargshah95 First advice would be to avoid W3Schools unless you already know what you're doing. Second, if you're just learning JavaScript, use the console--you don't need to write any HTML.

Dave Newton Over a year ago

@nisargshah95 The JavaScript console, available by default in Chrome, and maybe Firefox as well, if it isn't, install Firebug. Or use node.js.

DontVoteMeDown · Accepted Answer · 2013-12-19 17:58:22Z

3

This evaluates to a string:

(x==y).toString();

So you can use:

"<p>The result is " + (x==y).toString() + "</p>"

answered Dec 19, 2013 at 17:58

DontVoteMeDown

21.5k10 gold badges72 silver badges113 bronze badges

Comments

Victor Häggqvist · Accepted Answer · 2013-12-19 17:59:55Z

1

var x=1;
var y=2;
document.write("<p>The result is "+(x==y)+"</p>");

Will do

The result is false

answered Dec 19, 2013 at 17:59

Victor Häggqvist

4,4853 gold badges29 silver badges35 bronze badges

Collectives™ on Stack Overflow

How to incorporate a boolean value in a string in JavaScript

3 Answers 3

3 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related