keep duplicate strings in an array javascript code example
Example 1: javascript remove duplicate strings from array
let uniqueArray = [...new Set(arrayWithDuplicates)];
function removeArrayDuplicates(arrayWithDuplicates) {
let seen = {};
let uniqueArray = [];
let len = arrayWithDuplicates.length;
let j = 0;
for(let i = 0; i < len; i++) {
let item = arrayWithDuplicates[i];
if(seen[item] !== 1) {
seen[item] = 1;
uniqueArray[j++] = item;
}
}
return uniqueArray;
}
Example 2: check for duplicates in array javascript
[1, 2, 2, 4, 3, 4].filter((e, i, a) => a.indexOf(e) !== i)