需要使用< c:forEach>的帮助.在JSP/JSTL中

问题描述

我正在尝试遍历2d整数数组，并使用<table>标记在网格中表示它们.问题是我不允许使用任何Java脚本.我知道这是下面代码的作用，但更复杂.并且boardArray返回2d整数数组.那么我将如何提取每个单元格的值?数组也有预定大小.

I am trying to iterate through a 2d array of integers and represent them in a grid using the <table> tag. The catch is that I am not allowed to use any java-script. I know it is something to the effect of the below code, but more complicated. And boardArray returns a 2d integer array. So how would I extract the value at each cell? There is a predetermined size of the array as well.

       <c:forEach var="array" items="${bean.boardArray}">
            <tr>
                <td>${print out contents of a row}</td>
            </tr>
        </c:forEach>

推荐答案

使用纯HTML不能做到这一点.您在原始问题标题中提到了HTML，但是由于您已经附加了javabeans标记并提到了c:forEach标记，所以我想您的意思是JSP和JSTL而不是HTML.
在这里，JSP + JSTL解决方案的格式设置为易于阅读. Bean代码:

You can't do that with plain HTML. You've mentioned HTML in the original question title, but since you've attached the javabeans tag and mentioned the c:forEach tag, I suppose you mean JSP and JSTL instead of HTML.
Here the JSP+JSTL solution, formatted to be better readable. The bean code:

package com;

public class TransferBean {
    private int[][] _boardArray = {
        { 1, 2, 33, 0, 7},
        { 13, 11, 7, 5, 3},
        { 5, 3, 2, 1, 1},
    };


    public int[][] getBoardArray() {
        return _boardArray;
    }

    public int getBoardArrayRowLength() {
        if (_boardArray == null || _boardArray.length == 0
                || _boardArray[0] == null) {
            return 0;
        }

        return _boardArray[0].length;
    }
}

这里是JSP文件的内容:

Here the JSP file content:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<jsp:useBean id="bean" class="com.TransferBean" />

<table>
    <thead>
        <tr>
        <c:forEach var="i" begin="1" end="${bean.boardArrayRowLength}">
            <th>Column ${i}</th>
        </c:forEach>
        </tr>
    </thead>
    <tbody>
        <c:forEach var="row" items="${bean.boardArray}">
        <tr>
            <c:forEach var="column" items="${row}">
                <td>
                    ${column}
                </td>
            </c:forEach>
        </tr>
        </c:forEach>
    </tbody>
</table>

数组内容由两个嵌套的c:forEach循环呈现.外循环遍历行，对于每一行，嵌套循环遍历给定行中的列.

The array content is rendered by two nested c:forEach loops. The outer loop iterates over the rows, and for each row, the nested loop iterates over the columns in the given row.

上面的示例在浏览器中如下所示:

Above example looks like this in a browser:

这篇关于需要使用< c:forEach>的帮助.在JSP/JSTL中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！