JavaScript使用splice按索引删除数组元素

function RemoveValByIndex(arr, index) {
  arr.splice(index, 1);
}
test = new Array();
test[0] = 'Apple';
test[1] = 'Ball';
test[2] = 'Cat';
test[3] = 'Dog';
alert("Array before removing elements: "+test);
RemoveValByIndex(test, 2);
alert("Array after removing elements: "+test);