For Example, if you have given input string: ‘abc’ the result should be:

[ 'abc', 'acb', 'bac', 'bca', 'cab', 'cba']This problem can be solved by separating the first letter and find all permutations of the remaining letters. So for “abc” we can do:a bc a cb b ac b ca c ab c ba

Now first let’s convert this details into Pseudocode.

permutations(abc) = a + permutations(bc) + b + permutations(ac) + c + permutations(ab)permutations(ab) = a + permutations(b) + b + permutations(a)permutations(a) = a

Now We have enough understanding to convert this Pseudocode into an actual code.

```
function permutationsTest(inputstring) {
let results = [];
if (inputstring.length === 1) {
results.push(inputstring);
return results;
}
for (let i = 0; i < inputstring.length; i++) {
let firstChar = inputstring[i];
let charsLeft = inputstring.substring(0, i) + inputstring.substring(i + 1);
let innerPermutations = permutationsTest(charsLeft);
for (let j = 0; j < innerPermutations.length; j++) {
results.push(firstChar + innerPermutations[j]);
}
}
return results;
}
```