array splice vs non-splice

splice vs non-splice

function createObjectArray(length){
    var arr=[];
    for (var i=0;i<length;i++){
        var obj={
            id : "id_"+i,
            foo : "bar",
            value : i
        };
        arr.push(obj);
    }
    return arr;
}

function sortObjectArray(arr){
    arr.sort(function(a,b){
        return a.value-b.value;
    });
}




function useSwap(len){
    var move=len>>1;
    var arr=createObjectArray(len);

    console.time("useSwap");
    for (var i=0;i<move;i++){
        arr[len>>1]=arr[len-1]
        len--;
    }
    arr.length=len;
    // sortObjectArray(arr);
    console.timeEnd("useSwap");
}

function useSplice(len){
    var move=len>>1;
    var arr=createObjectArray(len);

    console.time("useSplice");
    for (var i=0;i<move;i++){
        arr.splice(len>>1,1);
        len--;
    }
    // sortObjectArray(arr);
    console.timeEnd("useSplice");
}


var arrayLength=2000;
useSwap(arrayLength);
useSplice(arrayLength);