JSFiddle - React, Tailwind, and code Playground
HTML
<div id='divId'>
</div>
JavaScript
var inText = 'programming';
var inArr = [];
for (var i=0; i<inText.length; i++) {
inArr[i] = inText.charAt(i);
}
inArr.sort();
var repoArr = [];
var idxArr = 0;
var idx = 0;
for (var i=idx; i<inArr.length; i++) {
if (inArr[idx] == inArr[i+1]) {
repoArr[idxArr++] = inArr[idx];
} else {
idx = i + 1;
}
}
$('#divId').text(repoArr.toString());