EXAMS - ODD OCCURENCES

odd_occurences.js

function solution(A) {
    // write your code in JavaScript (Node.js 4.0.0)
    var B = [];
    for(var i = 0; i < A.length; i++){
        var index = B.indexOf(A[i]);
        if(index > -1) B.splice(index, 1);
        else B.push(A[i]);
    }
    return B[0];
}

function solution(A) {
    // write your code in JavaScript (Node.js 4.0.0)
    var odd;
    for(var i = 0; i < A.length; i++){
        odd ^= A[i]; // exclusive or
    }
    return odd;
}