PHP学习笔记与Demo（二）

待我称王封你为后i 2022-03-25 11:23 218阅读 0赞

<?php
 /** * Created by PhpStorm. * User: wei19 * Date: 2019/1/19 * Time: 14:14 */
 /* * 多维数组创建及遍历 */
 $books = array(
 array('PHP','computer',42),
 array('VC++','computer',36),
 array('Arr','医学书籍',100),
 array('Science','英语',56)
 );
 echo "书籍名称：".$books[0][0]."书籍类型：".$books[0][1]."价格：".$books[0][2]." ";
 echo "书籍名称：".$books[1][0]."书籍类型：".$books[1][1]."价格：".$books[1][2]." ";
 echo "书籍名称：".$books[2][0]."书籍类型：".$books[2][1]."价格：".$books[2][2]." ";
 echo "书籍名称：".$books[3][0]."书籍类型：".$books[3][1]."价格：".$books[3][2]." ";
 echo "使用for循环来输出数组内容："." ";
 for ($i=0; $i<4;$i++){ 
 for ($j=0; $j<3; $j++){ 
 echo "@".$books[$i][$j];
 }
 echo " ";
 }
 //包含有描述性质的索引创建方式
 $book2 = array(
 array('bookName'=>'VC++','bookType'=>'computer','bookPrice'=>42),
 array('bookName'=>'PHP','bookType'=>'array','bookPrice'=>24),
 array('bookName'=>'VC','bookType'=>'science','bookPrice'=>48),
 array('bookName'=>'VC+','bookType'=>'book','bookPrice'=>98)
 );
 /* * 多维数组排序:usort() */
 //对$books按照书籍类型升序排序
 function ascending($x,$y){ 
 if ($x[0]==$y[0]){ 
 return 0;
 }else if ($x[0]<$y[0]){ 
 return -1;
 }else{ 
 return 1;
 }
 }
 //降序
 function descending($x,$y){ 
 if ($x[2]==$y[2]){ 
 return 0;
 }else if ($x[2]<$y[2]){ 
 return 1;
 }else{ 
 return -1;
 }
 }
 usort($books,'ascending');
 echo "按照书籍类型排序后："." ";
 for ($i=0;$i<4;$i++){ 
 for ($j=0;$j<3;$j++){ 
 echo "@".$books[$i][$j];
 }
 echo " ";
 }
 //对于相关数组，使用uasort()，uksort()排序
 function descending_book2($x,$y){ 
 if ($x['bookPrice']==$y['bookPrice']){ 
 return 0;
 }else if ($x['bookPrice']<$y['bookPrice']){ 
 return 1;
 }else{ 
 return -1;
 }
 }
 usort($book2,'descending_book2');//按照值排序
 foreach ($book2 as $key=>$value){ 
 foreach($value as $key2 => $value2){ 
 echo $key2.'=>'.$value2."~~~~~~~~"; //二维关联数组的遍历
 }
 echo " ";
 }
 /* * 知识点：数组函数 */