两个二维数组的合并

Question

合并前的数组a：array(size=3)0=>array(size=2)'id'=>string'113'(length=3)'email'=>string'[e-mail]'(length=24)1=>array(size=2)'id'=>string'111'(length=3)'email'=>string'[e-mail]'(length=24)2=>array(size=2)'id'=>string'109'(length=3)'email'=>string'[e-mail]'(length=19)合并前的数组b：array(size=2)0=>array(size=2)'user_id'=>string'113'(length=2)'count'=>string'1'(length=1)1=>array(size=2)'user_id'=>string'109'(length=2)'count'=>string'8'(length=1)合并后的数组（合并条件，a的id==b的user_id时合并）：array(size=3)0=>array(size=3)'id'=>string'113'(length=3)'email'=>string'[e-mail]'(length=24)'count'=>string'1'(length=1)1=>array(size=3)'id'=>string'111'(length=3)'email'=>string'[e-mail]'(length=24)'count'=>string'0'(length=1)2=>array(size=3)'id'=>string'109'(length=3)'email'=>string'[e-mail]'(length=19)'count'=>string'8'(length=1)

Answer 1

array_merge_recursive()函数与array_merge()函数一样，将一个或多个数组的元素的合并起来，一个数组中的值附加在前一个数组的后面。并返回作为结果的数组。但是，与array_merge()不同的是，当有重复的键名时，值不会被覆盖，而是将多个相同键名的值递归组成一个数组。（参见例子1）
"Horse","b"=>"Dog");$a2=array("c"=>"Cow","b"=>"Cat");print_r(array_merge_recursive($a1,$a2));?>输出：Array([a]=>Horse[b]=>Array([0]=>Dog[1]=>Cat)[c]=>Cow)