php 数组使用详解 推荐(3)


使用array_pad函数向数组尾部添加成员Array ( [0] => 80 [1] => 120 [2] => 160 [3] => 200 ) array_pad 还可以填充数组首部Array ( [0] => 40 [1] => 40 [2] => 40 [3] => 40 [4] => 80 [5] => 120 [6] => 160 [7] => 200 )


实例三:入栈操作追加(array_push):

复制代码 代码如下:


<?PHP
$num = array(1=>80,2=>120,3=>160);
array_push($num,200,240,280);//可以自己追加,直接加在数组结尾
print_r($num);
?>


运行结果:
Array ( [1] => 80 [2] => 120 [3] => 160 [4] => 200 [5] => 240 [6] => 280 )
实例四:array_unshift()在开头添加数组成员

复制代码 代码如下:


<?PHP
$num = array(1=>80,2=>120,3=>160);
array_unshift($num,0,40);//可以自己追加,直接加在数组结尾
print_r($num);
?>


运行结果:
Array ( [0] => 0 [1] => 40 [2] => 80 [3] => 120 [4] => 160 )
注意:array_unshift()函数使用后数组的键值将会从0开始!
     2.删减数组成员:
实例一:unset()命令删除数组成员或数组:

复制代码 代码如下:


<?PHP
$num = array_fill(0,5,rand(1,10));
print_r($num);
echo "<br />";
unset($num[4]);
print_r($num);
echo "<br />";
unset($num);
if(is_array){
echo "unset命令不能删除整个数组";
}else{
echo "unset命令可以删除数组";
}
?>


运行结果:(运行出错及说明数组也被删除,不再存在)

复制代码 代码如下:


Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 [4] => 9 )
Array ( [0] => 9 [1] => 9 [2] => 9 [3] => 9 )
Notice: Use of undefined constant is_array - assumed 'is_array' in H:\wamp\www\testing\editorplus\test.php on line 21
unset命令不能删除整个数组


实例二:array_splice()函数删除数组成员

复制代码 代码如下:


<?php
$a=array("red", "green", "blue", "yellow");
count ($a); //得到4
array_splice($a,1,1); //删除第二个元素
count ($a); //得到3
echo $a[2]; //得到yellow
echo $a[1]; //得到blue
?>


实例三:array_unique删除数组中的重复值:

复制代码 代码如下:


<?php
$a=array("red", "green", "blue", "yellow","blue","green");
$result = array_unique($a);
print_r($result);
?>


运行结果:
Array ( [0] => red [1] => green [2] => blue [3] => yellow )
实例四:array_merge、array_merge_recursive合并数组

复制代码 代码如下:


<?php
$array1 = array("r"=>"red",1,2,3,4);
$array2 = array("b"=>"blue",4=>5,6,7,8,9);
$array3 = array("r"=>"read",4=>10,2=>11);
$array4 = array(
array(4=>10),
array(7=>13)
);
$array5 = array(
array(4=>11),
array(6=>12)
);
$result = array_merge($array1,$array2,$array3,$array4,$array5);
echo "<pre>";
print_r($result);
echo "</pre>";
$result = array_merge_recursive($array1,$array2,$array3,$array4,$array5);
echo "<pre>";
print_r ($result);
echo "</pre>";
?>


运行结果:

复制代码 代码如下:


Array
(
[r] => read
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[b] => blue
[4] => 5
[5] => 6
[6] => 7
[7] => 8
[8] => 9
[9] => 10
[10] => 11
[11] => Array
(
[4] => 10
)
[12] => Array
(
[7] => 13
)
[13] => Array
(
[4] => 11
)
[14] => Array
(
[6] => 12
)
)
Array
(
[r] => Array
(
[0] => red
[1] => read
)
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[b] => blue
[4] => 5
[5] => 6
[6] => 7
[7] => 8
[8] => 9
[9] => 10
[10] => 11
[11] => Array
(
[4] => 10
)
[12] => Array
(
[7] => 13
)
[13] => Array
(
[4] => 11
)
[14] => Array
(
[6] => 12
)
)


注:1.array_merge的键名是数字的将重新建立索引;遇到相同的字符串键名时,后面的将覆盖前面的。
  2.array_merge_recursive函数的作用是将相同字符串的键名单元整合成一个数组。
  六、数组的键值和值操作:
实例一:in_array()检测数组中是否有某个值存在

复制代码 代码如下:

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