const arr = [];
for (let i = 0; i < 3; i++) {
// 세로
const cells = [];
for (let j = 0; j < 6; j++) {
// 가로
cells.push(0);
}
arr.push(cells);
}
console.log(arr);
/* 결과
[ [ 0, 0, 0, 0, 0, 0 ], [ 0, 0, 0, 0, 0, 0 ], [ 0, 0, 0, 0, 0, 0 ] ]
*/
const n = 3;
const m = 6;
const arr = Array.from(Array(n), () => new Array(m).fill(0));
console.log(arr);
/* 결과
[ [ 0, 0, 0, 0, 0, 0 ], [ 0, 0, 0, 0, 0, 0 ], [ 0, 0, 0, 0, 0, 0 ] ]
*/
const n = 3;
const m = 6;
const arr = Array(n).fill().map(() => Array(m).fill(0));
console.log(arr);
/* 결과
[ [ 0, 0, 0, 0, 0, 0 ], [ 0, 0, 0, 0, 0, 0 ], [ 0, 0, 0, 0, 0, 0 ] ]
*/