PHP合并两个数组的两种方式

echo "\r\n第一种情况\r\n";
$a=array(1,2,3,4,5,6);
$b=array(7,8,9);

$c=array_merge ($a,$b);
print_r($c);
$c=$a+$b;
print_r($c);
$c=$b+$a;
print_r($c);
echo "\r\n第二种情况\r\n";
$a=array('a','b','c','d','e','f');
$b=array('a','x','y');

$c=array_merge ($a,$b);
print_r($c);
$c=$a+$b;
print_r($c);
$c=$b+$a;
print_r($c);

echo "\r\n第三种情况\r\n";

$a=array(
 1=>'a',
 2=>'b',
 3=>'c',
 4=>'d',
 5=>'e',
 6=>'f');
$b=array(
 1=>'a',
 7=>'x',
 8=>'y');

$c=array_merge ($a,$b);
print_r($c);
$c=$a+$b;
print_r($c);
$c=$b+$a;
print_r($c);
?>

输出结果： 第一种情况 Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 [7] => 8 [8] => 9 ) Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 ) Array ( [0] => 7 [1] => 8 [2] => 9 [3] => 4 [4] => 5 [5] => 6 ) 第二种情况 Array ( [0] => a [1] => b [2] => c [3] => d [4] => e [5] => f [6] => a [7] => x [8] => y ) Array ( [0] => a [1] => b [2] => c [3] => d [4] => e [5] => f ) Array ( [0] => a [1] => x [2] => y [3] => d [4] => e [5] => f ) 第三种情况 Array ( [0] => a [1] => b [2] => c [3] => d [4] => e [5] => f [6] => a [7] => x [8] => y ) Array ( [1] => a [2] => b [3] => c [4] => d [5] => e [6] => f [7] => x [8] => y ) Array ( [1] => a [7] => x [8] => y [2] => b [3] => c [4] => d [5] => e [6] => f )