如何获取数组中数组的长度？

Question

I need to get length of an array inside an array for my iteration.

I have three arrays that contain names from three different majors in my college that nested in one array called 'jurusan' that means major in English.

and I want to put all that names into three new groups that contain names from three different majors and put it inside each group.

How can I access the length of the Array contained inside jurusan? my code reads the length of jurusan which is 3, it should get the length of tif array which is 5 and so on.

 var tif = ['idris', 'akbar', 'adyusman', 'a', 'g']; var te = ['tolaal', 'badri', 'alaina', 'b']; var mt = ['ressi', 'arian', 'tifa', 'c']; var jurusan = [tif, te, mt]; var kel = [ [], [], [] ]; for (i = 0; i < jurusan.length; i++) { for (j = 0; j < jurusan[i][j].length; j++) { kel[j].push(jurusan[i][j]); } } for (i = 0; i < kel.length; i++) { console.log(kel[i]) } document.getElementById("a").innerHTML = kel[0] + '<br>' + kel[1] + '<br>' + kel[2];

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Answer 1

How can I access the length of the Array contained inside jurusan?

It seems pretty straight to me:

 var tif = ['idris','akbar','adyusman','a','g']; var te = ['tolaal','badri','alaina','b']; var mt = ['ressi','arian','tifa','c']; var jurusan= [tif,te,mt]; // with forEach() jurusan.forEach(n => console.log(n.length)); // with index console.log(jurusan[0].length); console.log(jurusan[1].length); console.log(jurusan[2].length);

Answer 2

const input = [ ['a', 'b', 'c', 's', '1s'], ['c', 'd', 'f'], ['d', 'f', 'g', 'h'], ]; const arrayOfLength = (prop) => { let length = prop.map(num => num.length) console.log(length) } arrayOfLength(input)

// expected output [5, 3, 4]