What is the right way to check for a null string in Objective-C?

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梦毁少年i
梦毁少年i 2020-11-27 09:26

I was using this in my iPhone app

if (title == nil) {
    // do something
}

but it throws some exception, and the console shows that the ti

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  •  执念已碎
    2020-11-27 09:47

    If you want to test against all nil/empty objects (like empty strings or empty arrays/sets) you can use the following:

    static inline BOOL IsEmpty(id object) {
        return object == nil
            || ([object respondsToSelector:@selector(length)]
            && [(NSData *) object length] == 0)
            || ([object respondsToSelector:@selector(count)]
            && [(NSArray *) object count] == 0);
    }
    

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