Javascript array declaration (possibly mis-using length attribute?)

Question

I'm trying to get the innerHTML of red font tags...

var fontTags = document.getElementsByTagName('font');
var reds = [];
var j = 0;
var i = 0; // ETA this line
for (i;i<=fontTags.length;i++) { // ETA the 'i<='
  if (fontTags[i].getAttribute('color') == 'RED') {
    reds[j] = fontTags[i].innerHTML;
    j++;
  }
}

The javascript console is informing me that "fontTags[i]" is undefined. I've tried no declaration, declaring with 'new Array()'... same thing. Help?

You are leaking a global i and really shouldn't use <font> tags at all. — ThiefMaster
– ThiefMaster, Commented Apr 27, 2012 at 9:31
If fontTags.length is larger than 0, fontTags.length will always evaluate to true. Hence, at some moment i will be (equal) larger than fontTags.length. You want to compare it against the current counter, like i < fontTags.length. — Felix Kling
– Felix Kling, Commented Apr 27, 2012 at 9:31
isn't your condition always true? and i will grow more than the number of elements in the nodeList, thus fontTags[i] will be undefined. — Joseph
– Joseph, Commented Apr 27, 2012 at 9:31

Sirko · Accepted Answer · 2012-04-27 09:31:24Z

4

Your for loop is missing a proper loop-condition.

for (i=0;i<fontTags.length;i++) {
    if (fontTags[i].getAttribute('color') == 'RED') {
        reds[j] = fontTags[i].innerHTML;
        j++;
    }
}

answered Apr 27, 2012 at 9:31

Sirko

74.3k19 gold badges157 silver badges194 bronze badges

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

3 Comments

Moose Over a year ago

Apologies. See edit for fixed code. I still see the same error, however.

antoniuslin Over a year ago

it's what sirko wrote, but your condition is still in error. less than; and not less than or equal to.

Moose Over a year ago

Yes, because I'm starting at zero, and the length doesn't... duh. Thank you :)

sushil bharwani · Accepted Answer · 2012-04-27 09:33:28Z

0

for (i=0;i<fontTags.length;i++) {

check the for loop condition

answered Apr 27, 2012 at 9:33

sushil bharwani

30.2k30 gold badges98 silver badges130 bronze badges

Comments

Nagaraju Badaeni · Accepted Answer · 2012-04-27 09:34:01Z

0

use


for(i=0;i<fontTags.length;i++)

instead for (i=0;fontTags.length;i++)

answered Apr 27, 2012 at 9:34

Nagaraju Badaeni

9008 silver badges14 bronze badges

Collectives™ on Stack Overflow

Javascript array declaration (possibly mis-using length attribute?)

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