Array Manipulator

//08. Array Manipulator
function manipolator(sequence, operations) {

    let newArr = sequence.slice();
    let outPrint = 0;
    let contains = 0;
    let flag = false;

    for (let i = 0; i < operations.length; i++) {

        let splited = operations[i].split(' ')
        let command = [];

        for (let ind = 0; ind < splited.length; ind++) {
            command.push(splited[ind]);
        }
        switch (command[0]) {
            case "add":
                newArr.splice(command[1], 0, Number(command[2]));
                break;
            case "addMany":
                let newPosion = Number(command[1]);
                for (let many = 1; many < command.length - 1; many++) {
                    newArr.splice(newPosion, 0, Number(command[many + 1]));
                    newPosion++;
                }
                break;
            case "contains":
                flag = true;
                console.log(newArr.indexOf(Number(command[1])));
                break;
            case "remove":
                newArr.splice(command[1], 1)

                break;
            case "shift":
                let tempo = newArr.slice(0, command[1]);
                for (let a of tempo) {
                    newArr.push(a);
                    newArr.shift();
                }
                break;
            case "sumPairs":
                sumPairs()
                break;
            case "print":
                break;
        }
    }
    function fn(x) {
        newArr.push(newArr[many + 1])
    }

    function sumPairs() {
        newArr = newArr.map((e, i, newArr) => i < newArr.length - 1 ? (newArr[i] += newArr[i + 1]) : newArr[i] = newArr[i]).filter((e, i) => i % 2 === 0);
    }

    console.log('[ ' + newArr.join(', ') + ' ]');
    //console.log(newArr.map(Number));

}
//manipolator([1, 2, 4, 5, 6, 7], ['add 1 8', 'contains 1', 'contains 3', 'print']);
// manipolator([2, 2, 4, 2, 4], ["add 1 4", "sumPairs", "print"])
//manipolator([1, 2, 3, 4, 5], ["addMany 5 9 8 7 6 5", "contains 15", "remove 3", "shift 1", "print"])
manipolator([2, 2, 4, 2, 4],["add 1 4", "sumPairs", "print"]);