php一维数组合并的三种方式对比
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2022-04-08 15:34:03
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php数组合并有三种方式:array_merge,array_merge_recursive,+(就是数学运算符加号); 下面是一段对比的代码 $array1 = array(2,4,"color" = "red"); $array2 = array("a", "b", "color" = "green", "shape" = "trapezoid", 4); $result = array_merge($array
php数组合并有三种方式:array_merge,array_merge_recursive,+(就是数学运算符加号);
下面是一段对比的代码
$array1 = array(2,4,"color" => "red"); $array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 4); $result = array_merge($array1, $array2); echo "----------------array_merge---------------".PHP_EOL; print_r($result); echo "----------------+++++++++++---------------".PHP_EOL; print_r($array1+$array2); echo "----------------array_merge_recursive---------------".PHP_EOL; print_r(array_merge_recursive($array1,$array2));
结果如下所示
----------------array_merge--------------- Array ( [0] => 2 [1] => 4 [color] => green [2] => a [3] => b [shape] => trapezoid [4] => 4 ) ----------------+++++++++++--------------- Array ( [0] => 2 [1] => 4 [color] => red [shape] => trapezoid [2] => 4 ) ----------------array_merge_recursive--------------- Array ( [0] => 2 [1] => 4 [color] => Array ( [0] => red [1] => green ) [2] => a [3] => b [shape] => trapezoid [4] => 4 )
对比array_merge和+以及array_merge_recursive结果的”color”的值我们可以看出:
1.对于相同的字符串索引,
array_merge则会用后面的值覆盖前面出现的值;
+会用前面出现过的值覆盖后面相同的key;
array_merge_recursive则会把相同的索引放到一个数组里面,增加数组的维度;
2.对于相同的数字索引,
array_merge则会给重复的值重建索引(索引值从0开始);
+仍然是用前面出现过的值覆盖后面的值;
array_merge_recursive和array_merge的处理方法一样。
原文地址:php一维数组合并的三种方式对比, 感谢原作者分享。
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