How to Find All Occurrences of an Element in a JavaScript Array?

Retrieve Indexes of Element Occurrences in Array

When attempting to locate the positions of multiple instances of an element, such as "Nano," within a JavaScript array, methods like jQuery.inArray or .indexOf() fall short as they only identify the last occurrence.

var Cars = ["Nano", "Volvo", "BMW", "Nano", "VW", "Nano"];

Here's the solution:

The .indexOf() method allows for specifying a starting index, enabling you to loop through the array and pinpoint all instances of the specified value.

<code class="javascript">function getAllIndexes(arr, val) {
  var indexes = [],
    i = -1;
  while ((i = arr.indexOf(val, i + 1)) != -1) {
    indexes.push(i);
  }
  return indexes;
}

var indexes = getAllIndexes(Cars, "Nano");</code>

However, as pointed out by VisioN in the comments, a straightforward for loop offers a more efficient and concise solution:

<code class="javascript">function getAllIndexes(arr, val) {
  var indexes = [],
    i;
  for (i = 0; i < arr.length; i++) {
    if (arr[i] === val) {
      indexes.push(i);
    }
  }
  return indexes;
}</code>

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