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array_diff()
函数返回多个数组的差集数组,键名不进行比较,返回与第一个数组相比,第一个数组没有的值(数组)
形式:array_diff(array1,array2,array3...);
例子:
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"black","g"=>"purple");
$a3=array("a"=>"red","b"=>"black","h"=>"yellow");
// $result=array_diff($a1,$a2,$a3);//Array ( [b] => green => blue )
$result=array_diff($a1,$a2);//Array ( [b] => green => blue [d] => yellow )
array_change_key_case()
将数组的所有的键都转换为大写字母或小写字母
形式:array_change_key_case(array,case);
case可选值CASE_LOWER小写(默认) CASE_UPPER 大写
例子:
$age=array("Bill"=>"60","Steve"=>"56","Mark"=>"31");
print_r(array_change_key_case($age));// Array ( [bill] => 60 [steve] => 56 [mark] => 31 )
print_r(array_change_key_case($age,CASE_LOWER));// Array ( [bill] => 60 [steve] => 56 [mark] => 31 )
print_r(array_change_key_case($age,CASE_UPPER));//Array ( [BILL] => 60 [STEVE] => 56 [MARK] => 31 )
array()
array_chunk()
将数组按数量分为多个数组
形式:array_chunk(array,size[,preserve_key]);
preserve_key的参数:true保留原始键名 false(默认)不保留原始键名
例子:
$cars=array("Volvo","BMW","Toyota","Honda","Mercedes");
print_r(array_chunk($cars,2));
// Array ( [0] => Array ( [0] => Volvo [1] => BMW )
// [1] => Array ( [0] => Toyota [1] => Honda )
// [2] => Array ( [0] => Mercedes ) )
array_column()
返回输入数组中某个单一列的值。
形式:array_column(array,column_key[,index_key]);
column_key:单列的键名
index_key:返回数组的索引,比如用id作为键名...不写则从零依次递加
例子:
$a = array( array( 'id' => 5698, 'first_name' => 'Bill', 'last_name' => 'Gates', ), array( 'id' => 4767, 'first_name' => 'Steve', 'last_name' => 'Jobs', ), array( 'id' => 3809, 'first_name' => 'Mark', 'last_name' => 'Zuckerberg', ) ); $last_names = array_column($a, 'last_name', 'id'); print_r($last_names); //Array ( [5698] => Gates [4767] => Jobs [3809] => Zuckerberg ) //Array ( [0] => Gates [1] => Jobs [2] => Zuckerberg )
array_combine()
通过两个数组创建新的数组
形式:array_combine(keys,values);
第一个是键名,第二个是键值
键名与键值要数量相同,否则报错
例子:
$fname=array("Bill","Steve","Mark","ceshi");
$age=array("60","56","31","1");
$c=array_combine($fname,$age);
print_r($c);
// Array ( [Bill] => 60 [Steve] => 56 [Mark] => 31 [ceshi] => 1 )
array_count_values()
用于统计数组中所有值出现的次数
形式:array_count_values(array)
例子:
$a=array("A","Cat","Dog","A","Dog");
print_r(array_count_values($a));
// Array ( [A] => 2 [Cat] => 1 [Dog] => 2 )
