javascript - javascript array turns to be undefined

Question

Input: nums = [1,2,3,4] Output: [1,3,6,10] Explanation: Running sum is obtained as follows: [1, 1+2, 1+2+3, 1+2+3+4].

var runningSum = function(nums) {
    const array = new Array (nums.length);
    array[0] = nums[0];
    for( let i=1; i<nums.length; i++){
        array[i] = nums[i] + array[i-1]
    }
};

the result turns out to be undefine, I don't know where I did wrong.

标签： javascriptarrays

Answer 1

你必须返回数组

所以

var runningSum = function(nums) {
    const array = new Array (nums.length);
    array[0] = nums[0];
    for( let i=1; i<nums.length; i++){
        array[i] = nums[i] + array[i-1]
    }
    return array;
};

代替

var runningSum = function(nums) {
    const array = new Array (nums.length);
    array[0] = nums[0];
    for( let i=1; i<nums.length; i++){
        array[i] = nums[i] + array[i-1]
    }
};