使用指令 if?

if(isset($something['say']) && $something['say'] === 'bla') {
    // do something
}

顺便说一下，您使用 say 键为一个值赋值了两次，因此您的数组将生成一个只有一个值的数组.

By the way, you are assigning a value with the key say twice, hence your array will result in an array with only one value.