<header> <h1>Flat</h1> </header> <body> <script> arr = []; for (let i = 0; i < 5; i++) { arr[i] = []; for (let j = 0; j < 5; j++) { arr[i][j] = (i + 1) * (j + 1); } } const arrCopy = [...arr[0], ...arr[1], ...arr[2], ...arr[3], ...arr[4]]; alert(arrCopy); </script> </body>
