even odd substraction

function  solve(arr){

    let arrayEven = [];
    let arrayOdd = [];

    let evenSum = 0;
    let oddSum = 0;

    for (let i = 0; i < arr.length; i++) {
        let number = arr[i];

        if (number % 2 == 0){
            arrayEven.push(number);
        }
        else{
            arrayOdd.push(number);
        }

    }

    if (arrayEven.length > 0){
        evenSum = arrayEven.reduce((a, b) => a + b);
    }

    if (arrayOdd.length > 0){
        oddSum = arrayOdd.reduce((a, b) => a + b);
    }

    let sum = evenSum - oddSum;

    console.log(sum);

}