JavaScript Lonely integer problem : Code not working in JS

[joji]

I am trying to resolve a hackerrank challenge in javascript and even if my code is logic it is giving me the wrong answer each time.. Here is my code :

function lonelyinteger(a) {
// Write your code here
if (a.length==1){return a[0];}
if (a.length>1 && a.length<100) {
for(let i = 0; i <=a.length; i++){
for(let j=0;j<=a.length && j!=i;j++){
if (a==a[j]){
a.splice(j,1);
a.splice(i,1);}
}
}return a[0];

}

}

The lonelyInteger function takes an array of integer (in which there are elements duplicated ounce and its length is odd number + this array always contains only one element which is not duplicated) and rreturns the non duplicated element. My approach is to check all the duplicates --> remove them from the array --> Result : my array contains only the non duplicated element in the end so I return it

This is not working for me, where is the problem can you help me please ?

Thanks in advance !

I runned the code many times, evethough the length of the returned list is not 1 as expected means the splice function is not doing the job properly

 

[OldMan]

I don't like
&& j != i;

j and i are going to be equal a number of times. When the loops first start they both equal 0. Remove it and see what happens.

 

[Deleted member 2829]

And I don't like
if (a==a[j])
Comparing the entire array with its first element ? This will either return always false, or more likely gives an error - did you check console output ?

I also don't like that you loop through the array, based on its length, and then inside the loop remove remove elements from the array so that its length changes. Maybe it works but I would not rely on JS re-evaluating the length with every iteration. I you really want to do it this way at least work on a copy of the array.

Personally I would sort the array, then loop through it once and find the lone number that has different numbers on each side of it (first and last number of course have to be checked separately). If you are also required to find the index of the lone integer this does not work of course - but nor does your solution.