📜  如何在快速代码示例中检查对象为零

📅  最后修改于: 2022-03-11 15:01:01.847000             🧑  作者: Mango

代码示例1
if let variableName = abc { // If casting, use, eg, if let var = abc as? NSString
    // variableName will be abc, unwrapped
} else {
    // abc is nil
}