+ 1

Can anyone explain those codes?

var arr = []; arr[0] = arr.length; arr[1] = arr.length + 4; arr[2] = arr.length + arr[1] %2; document.write(arr[2]) //output = 3 var arr = []; arr[1] = 4; arrr[0] = arr.length; arr[2] = arr.length; document.write(arr[0]+arr[2]%arr[1]) //output= 4 Why so??? I can't understand the arr.length... It'snot stay constant in the first code...Like its length for arr[0]=0,and it's lenghth for arr[1]=1. But in the second code it's length is 2 for arr[0],arr[2]...why it is not 0 for arr[0] and 2 for arr[2]??? I can't understand... please explain

7th Oct 2018, 5:24 AM
ASHITAKA
ASHITAKA - avatar
1 Odpowiedź
+ 3
Length is updated as elements are removed from or added to the array. var arr = []; // Empty array, length = 0 arr[0] = arr.length; // Element added, arr[0] = 0, length = 1. arr[1] = arr.length + 4; // Element added, arr[1] = 5, length = 2. arr[2] = arr.length + arr[1] %2; // arr[2] = 2 + 5 % 2 = 3 //================= var arr = []; // Empty array, length = 0 arr[1] = 4; // 2 elements added, arr[0] = undefined, arr[1] = 4, length = 2. arr[0] = arr.length; // Element modified, arr[0] = 2. arr[2] = arr.length; // Element added, arr[2] = 2, length = 3. document.write(arr[0] + arr[2] % arr[1]) // 2 + 2 % 4 = 4.
7th Oct 2018, 6:18 AM
Hoàng Nguyễn Văn
Hoàng Nguyễn Văn - avatar