CODEWITHSUNDEEP
javascriptarraysregex
wyc
wyc

Reputation: 55293

Why is the following if statement excluding an array that's identical to the rest?

I have the following array of arrays:

[ 'markdown',
  [ 'para', '"one"' ],
  [ 'hr' ],
  [ 'para', '"two"' ],
  [ 'para', '"three"' ] ]

I made a loop to only match those arrays with double quotes:

for (i = 1; i < jsonml.length; i++) {

      if (typeof jsonml[i][1] === "string" && jsonml[i][1].match(/"/g)) {
        var p = jsonml[i]
        console.log(p)
      }

      // more code

      if (jsonml[i][0] === 'hr') {
        var hr = jsonml[i]
        var p = jsonml[i + 1]

        hr.splice(0, 1, 'para', '* * *')
        p.splice(1, 0, {'class': 'noind'})
      }

For some reason console.log(p) only outputs:

[ 'para', '"one"' ]
[ 'para', '"three"' ]

Is [ 'hr' ] somehow making [ 'para', '"two"' ] not to match the if statement? If so how to fix it so that [ 'para', '"two"' ] is matched, too? 

 if (jsonml[i][0] === 'hr') {
    var hr = jsonml[i]
    var p = jsonml[i + 1]

    hr.splice(0, 1, 'para', '* * *')
    p.splice(1, 0, {'class': 'noind'})
  }

EDIT:

I think the problem is with the if statement below, since console.log(jsonml[i][1]) outputs:

"one"
undefined
{ class: 'noind' }
"three"

I thought the if statements would execute in order?

Upvotes: 0

Views: 47

Answers (1)

musefan
musefan

Reputation: 48425

The problem appears to be because you are modifying the array while you are still iterating over it. Which means that the [ 'para', '"two"' ] item is no longer there by the time you get round to it.

Usually, you should always avoid modifying a collection while you are looping over it. If you need to make changes then do them either before or afterwards (which can also be using a separate loop if you need to)

Upvotes: 4

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