CODEWITHSUNDEEP
loopsflutterdart
Yonkee
Yonkee

Reputation: 1883

Get index of Item in Loop to match against stored Indices

I have a scenario where I want to perform an action if a string in a list of string matches the index in a list of ints (Generated based on String list )

The below is some pseudo code to try and articulate what I am trying to achieve. 

List<int> wordIndex = [1,3,5];
List<String> wordList = ['this', 'is','a', 'test', 'a'];

//Pseudo code
wordList.forEach(word)) {
 if (wordIndex item matches index of word) {
    do something;
  } else {
    od something else;
 }
}

it the if (wordIndex item matches index of word) where I am having a problem and would appreciate any ideas.

Upvotes: 1

Views: 76

Answers (2)

creativecreatorormaybenot
creativecreatorormaybenot

Reputation: 126624

If I understand you correctly, you want to know if the index of a word is contained in you wordIndex list, i.e. you want to get all wordList items with an index that is stored in wordIndex.

There are two approaches to this:

Use Iterable.contains

In this case, we are simple checking if the current index is present in the wordIndex list.

for (var index = 0; index < wordList.length; index++) {
  if (wordIndex.contains(index)) {
    // do something
    return;
  }

  // do something else
}

Loop through wordIndex

If you are just interested in the matching items, this approach is more reasonable.
Here, we loop through the index list and then simply get the matching elements in the wordList. However, you will not be able to take actions for the non-matching items:

for (final index in wordIndex) {
  final word = wordList[index];

  // do something
}

Upvotes: 0

Ali Bayram
Ali Bayram

Reputation: 7921

Just use for instead of forEach;

List<int> wordIndex = [1,3,5];
List<String> wordList = ['this', 'is','a', 'test', 'a'];

//Pseudo code
for (int i = 0; i < wordList.length; i++) {
  if (wordIndex.contains(i)) {
    do something;
  } else {
    od something else;
 }
}

Upvotes: 1

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