append-arr-or-num.ts

function append(
    arrOrNum: number | number[],
    toAppendArrOrNum: number | number[]): number[] {

    if (!Array.isArray(arrOrNum)) {
        arrOrNum = [arrOrNum];
    }

    if (!Array.isArray(toAppendArrOrNum)) {
        toAppendArrOrNum = [toAppendArrOrNum];
    }

    return arrOrNum.concat(toAppendArrOrNum);
}