<style> #output span { display: inline-block; width: 100px; height: 40px; margin: 5px; line-height: 40px; text-align: center; background-color: #ccc; } #output span:hover { background-color: #fc0; color: #fff; } </style> </head> <body> <h1>打印99乘法表</h1> <div id="output"> </div> </body> <script>where = document.getElementById Output ( 'Output' ); var HTML = ''; // prepare holds string for ( var I =. 1; I <=. 9; I ++ ) { // outer loop: loop rows for ( var J =. 1; J <= I; J ++ ) { // inner loop: cyclic number html + = '<span>' + i + 'x' + j + '=' + i * j + '</ span>' ; } HTML + = '<br />' ; } output.innerHTML = HTML; </ Script>
For just learning js, the exercise about logic