Javascript for loop not adding up correctly

Question

I get size of the PDF files within the name of the the file on page

console.log($(opt).text() + " selected")

opt has the value such as abcs{853269}

I get the value using regular expression:

var curSize = $(opt).text();
console.log(curSize + "current Size");

var counter = 0;
var result = curSize.match(/{(.*?)}/);
console.log('sizee' + result);

The console result is {853269},853269

I don't know why I am getting two results, I thought regex will only return one.

Now I have a for loop to calculate all the values that are selected and give it back to me as one big sum:

if ( result !=null){
    for(var i=0; i< result.length; i++){
        counter += result[i];
        document.getElementById("textarea").value += result[i];
    }
    console.log(counter + "Counter");
}

...but it's crashing.

result[0] is the whole match, and the rest of the elements are the contents of the capturing groups. result[1] is what you want. — Alan Moore
– Alan Moore, Commented May 15, 2016 at 22:08

Paarth · Accepted Answer · 2016-05-15 22:07:43Z

1

If you take a look at the regex documentation you can see it returns:

An Array containing the entire match result and any parentheses-captured matched results, or null if there were no matches.

Your first item in the array is the entire expression that was matched by the regex. The second item that you see is the value extracted from the match group (your parenthesis). Use the second value directly.

var result = curSize.match(/{(.*?)}/);

var extractedText = undefined;
if(result) {
    extractedText = result[1];
}

answered May 15, 2016 at 22:07

Paarth

10.5k4 gold badges30 silver badges37 bronze badges

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

Comments

Brynden · Accepted Answer · 2016-05-15 22:10:43Z

0

Here's what MDN says about String.prototype.match (page):

The match() method retrieves the matches when matching a string against a regular expression.

With your current regular expression, there's an item (in the array returned from String.match) for a match to the entire regular expression. That explains the first result ({853269}).

The second item in the resulting array (853269), is coming from the group that you defined in your regular expression.

answered May 15, 2016 at 22:10

Brynden

38.3k2 gold badges18 silver badges22 bronze badges

Collectives™ on Stack Overflow

Javascript for loop not adding up correctly

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related