PHP数组使用

  1 php删除数组首个元素
  2 $a=array("a"=>"red","b"=>"green","c"=>"blue");
  3 echo array_shift($a);
  4 print_r ($a);
  5 red        Array ( [b] => green [c] => blue )
  6 
  7 
  8 合并数组
  9 $a1=array('a'=>'aaa');
 10 $a2=array('b'=>'bbb');
 11 dd(array_merge($a1,$a2));
 12 array:2 [▼
 13   "a" => "aaa"
 14   "b" => "bbb"
 15 ]
 16 
 17 
 18 返回所有的key
 19 $a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander");
 20 dd(array_keys($a));
 21 array:3 [▼
 22   0 => "Volvo"
 23   1 => "BMW"
 24   2 => "Toyota"
 25 ]
 26 
 27 
 28 返回所有value
 29 $a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander");
 30 dd(array_values($a));
 31 array:3 [▼
 32   0 => "XC90"
 33   1 => "X5"
 34   2 => "Highlander"
 35 ]
 36 
 37 
 38 array_filter使用
 39 $arr = ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4];
 40 
 41 var_dump(array_filter($arr, function($value) {
 42     return $value == 4;
 43 }));
 44 
 45 var_dump(array_filter($arr, function($k) {
 46     return $k == 'b';
 47 }, ARRAY_FILTER_USE_KEY));
 48 
 49 var_dump(array_filter($arr, function($v, $k) {
 50     return $k == 'b' || $v == 4;
 51 }, ARRAY_FILTER_USE_BOTH));
 52 
 53 
 54 array_change_key_case使用
 55 $arr = ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4];
 56 $a=array_change_key_case($arr,CASE_UPPER);
 57 dd($a);
 58 array:4 [▼
 59   "A" => 1
 60   "B" => "b"
 61   "C" => 3
 62   "D" => 4
 63 ]
 64 
 65 array_chunk分割数组
 66 $arr = ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4];
 67 $a2=array_chunk($arr,2,true);//第三个参数默认false返回value，ture返回整个数组
 68 dd($a2);
 69 array:2 [▼
 70   0 => array:2 [▼
 71     "a" => 1
 72     "b" => 2
 73   ]
 74   1 => array:2 [▼
 75     "c" => 3
 76     "d" => 4
 77   ]
 78 ]
 79 
 80 
 81 array_column 取数组一列
 82 $records = array(
 83     array(
 84         'id' => 2135,
 85         'first_name' => 'John',
 86         'last_name' => 'Doe',
 87     ),
 88     array(
 89         'id' => 3245,
 90         'first_name' => 'Sally',
 91         'last_name' => 'Smith',
 92     ),
 93     array(
 94         'id' => 5342,
 95         'first_name' => 'Jane',
 96         'last_name' => 'Jones',
 97     ),
 98     array(
 99         'id' => 5623,
100         'first_name' => 'Peter',
101         'last_name' => 'Doe',
102     )
103 );
104 $first_names = array_column($records, 'first_name');
105 dd(implode(',',$first_names));
106 输出:"John,Sally,Jane,Peter"
107 
108 
109 array_combine 合并数组，key,value方式合并
110 $a = array('green', 'red', 'yellow');
111 $b = array('avocado', 'apple', 'banana');
112 $c = array_combine($a, $b);
113 print_r($c);
114 
115 Array ( [green] => avocado [red] => apple [yellow] => banana )
116 
117 
118 array_flip互换key和value
119 $input = array("a" => 1, "b" => 1, "c" => 2);
120 $flipped = array_flip($input);
121 dd($flipped);
122 array:2 [▼
123   1 => "b"
124   2 => "c"
125 ]
126 
127 array_map用法
128 $a = array(1, 2, 3, 4, 5);
129 $b = array("uno", "dos", "tres", "cuatro", "cinco");
130 dd(array_map(
131     function($k,$v){
132         return("The number $k  is called $v in Spanish");
133     },$a,$b
134 ));
135 $c =array_combine($a,$b);
136 array:5 [▼
137   0 => "The number 1  is called uno in Spanish"
138   1 => "The number 2  is called dos in Spanish"
139   2 => "The number 3  is called tres in Spanish"
140   3 => "The number 4  is called cuatro in Spanish"
141   4 => "The number 5  is called cinco in Spanish"
142 ]