PHP （20140523）

sort();  升序

 对数组排序；

 1 <?php
 2 
 3 $fruits  = array( "lemon" ,  "orange" ,  "banana" ,  "apple" );
 4 sort ( $fruits );
 5 foreach ( $fruits  as  $key  =>  $val ) {
 6     echo  "fruits["  .  $key  .  "] = "  .  $val  .  "
" ;
 7 }
 8 
 9 ?>
10 //输出结果
11 
12 fruits[0] = apple
13 fruits[1] = banana
14 fruits[2] = lemon
15 fruits[3] = orange

rsort();降序

-对数组逆向排序

此函数为 array 中的元素赋与新的键名。这将删除原有的键名，而不是仅仅将键名重新排序。

<?php
$fruits  = array( "lemon" ,  "orange" ,  "banana" ,  "apple" );
rsort ( $fruits );
foreach ( $fruits  as  $key  =>  $val ) {
    echo  " $key  =  $val 
" ;
}
?> 
//以上例程会输出：

0 = orange
1 = lemon
2 = banana
3 = apple

arsort();升序

对数组进行逆向排序并保持索引关系

<?php
$fruits  = array( "d"  =>  "lemon" ,  "a"  =>  "orange" ,  "b"  =>  "banana" ,  "c"  =>  "apple" );
arsort ( $fruits );
foreach ( $fruits  as  $key  =>  $val ) {
    echo  " $key  =  $val 
" ;
}
?> 
//以上例程会输出：

a = orange
d = lemon
b = banana
c = apple

asort();降序

对数组进行排序并保持索引关系；排值。

<?php
$fruits  = array( "d"  =>  "lemon" ,  "a"  =>  "orange" ,  "b"  =>  "banana" ,  "c"  =>  "apple" );
asort ( $fruits );
foreach ( $fruits  as  $key  =>  $val ) {
    echo  " $key  =  $val 
" ;
}
?> 
//以上例程会输出：

c = apple
b = banana
d = lemon
a = orange

ksort();升序

对数组按照键名排序。

<?php
$fruits  = array( "d" => "lemon" ,  "a" => "orange" ,  "b" => "banana" ,  "c" => "apple" );
ksort ( $fruits );
foreach ( $fruits  as  $key  =>  $val ) {
    echo  " $key  =  $val 
" ;
}
?> 
//以上例程会输出：

a = orange
b = banana
c = apple
d = lemon

krsort ();降序

 对数组按照键名逆向排序

 

<?php
$fruits  = array( "d" => "lemon" ,  "a" => "orange" ,  "b" => "banana" ,  "c" => "apple" );
krsort ( $fruits );
foreach ( $fruits  as  $key  =>  $val ) {
    echo  " $key  =  $val 
" ;
}
?> 
//以上例程会输出：

d = lemon
c = apple
b = banana
a = orange