<script> let 전교점수 = [ //1반 [[10, 20, 30, 40, {name:'velog', age: 10}], [20, 30, 40, 50, 60,]], //2반 [[10, 20, 30, 40, 50,], [20, 30, 40, 50, 60]], ]; console.log(전교점수[0][1][4]['age']); //matrix let m = [[1, 2, 3], [1, 2, 3], [1, 2, 3]]; </script>