代码编辑器：
x
1
2
$a=array("Volvo","BMW");3
if (array_key_exists(0,$a))4
{5
echo "Key exists!";6
7
} else {8
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echo "Key does not exist!";10
}11
$a=array("Volvo","BMW");if (array_key_exists(0,$a)){ echo "Key exists!";} else { echo "Key does not exist!";}