how do I add these strings and not concatenate them

Question

My code just purely concatnates them and I want it to add them instead.

 <FORM NAME="Calc">
<TR>
<TD>
Number 1 <INPUT TYPE="text"   NAME="n1" Size="16">
Number 2 <INPUT TYPE="text"   NAME="n2" Size="16">
Answer<INPUT TYPE="text"   NAME="ans" Size="16">

<br>
</TD>
</TR>
<TR>
<TD>
<INPUT TYPE="button" NAME="one"   VALUE="  +  " OnClick="Calc.ans.value = eval(Calc.n1.value + Calc.n2.value)">

JLRishe · Accepted Answer · 2014-04-11 12:42:05Z

10

Like this:

Calc.ans.value = (+Calc.n1.value) + (+Calc.n2.value);

You don't need to use eval() here. In fact, you should (almost) never use eval().

answered Apr 11, 2014 at 12:42

JLRishe

102k19 gold badges138 silver badges171 bronze badges

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

Comments

Aadrinmusic · Accepted Answer · 2014-04-11 12:48:05Z

1

This works:

Calc.ans.value = parseInt(Calc.n1.value) + parseInt(Calc.n2.value)

answered Apr 11, 2014 at 12:48

Aadrinmusic

1241 silver badge9 bronze badges

Comments

Community · Accepted Answer · 2017-05-23 12:27:13Z

0

This is more safe (see this):

Calc.ans.value = parseInt(Calc.n1.value, 10) + parseInt(Calc.n2.value, 10)

edited May 23, 2017 at 12:27

CommunityBot

11 silver badge

answered Apr 11, 2014 at 13:06

leo

1,2631 gold badge18 silver badges20 bronze badges

2 Comments

JLRishe Over a year ago

It's safer than using parseInt() without a radix, but the + operator doesn't have the issue mentioned in the page you linked to. Plus, are you sure that the numbers OP wants to use are limited to integers?

leo Over a year ago

Yes, I agree with you! ;)

Collectives™ on Stack Overflow

how do I add these strings and not concatenate them

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related