function compressArray(original) { var compressed = []; // make a copy of the input array var copy = original.slice(0); // first loop goes over every element for (var i = 0; i < original.length; i++) { var myCount = 0; // loop over every element in the copy and see if it's the same for (var w = 0; w < copy.length; w++) { if (original[i] == copy[w]) { // increase amount of times duplicate is found myCount++; // sets item to undefined delete copy[w]; } } if (myCount > 0) { var a = new Object(); a.value = original[i]; a.count = myCount; compressed.push(a); } } return compressed; };
It should go something like this:
var testArray = new Array("dog", "dog", "cat", "buffalo", "wolf", "cat", "tiger", "cat"); var newArray = compressArray(testArray); /* console: [ Object { value="dog", count=2}, Object { value="cat", count=3}, Object { value="buffalo", count=1}, Object { value="wolf", count=1}, Object { value="tiger", count=1} ] */
