Objc ﹣ property ﹣ t is often used in actual development, for example, it is necessary to obtain the property of a registered class, or judge the type of property, or automatically assign a value to the property after obtaining the property, etc

Here is an example of obtaining all the properties of a registered class. The code is as follows:

//Get all property names of a class
- (NSArray*)getPropertieNamesByObject:(id)object
{
    
    unsigned int outCount, i;
    
    // Obtain the property list of the registered class. The first parameter is the class, and the second parameter is the variable that receives the number of class properties
    objc_property_t *properties = class_copyPropertyList([object class], &outCount);
    //Define an array to receive the acquired property name
    NSMutableArray *nameArray = [[NSMutableArray alloc] initWithCapacity:outCount];
    for (i = 0; i < outCount; i++) {
        //Loop to get a single attribute
        objc_property_t property = properties[i];
        //Get attribute name
        NSString *propertyName = [[NSString alloc] initWithCString:property_getName(property) encoding:NSUTF8StringEncoding];
        //Put the resulting property name into the array
        [nameArray addObject:propertyName];
        
    }
    free(properties);
    return nameArray;
}

If you want to determine the type of the property, you only need to get the value of the property of the object through valueForKey:, and then determine the type of the value.

And if you want to get the member variables of a class, how to do it?
The method is as follows:

//Get the member variable name of the class
- (NSArray *)getVariableNamesByObject:(id)object
{
    unsigned int numIvars = 0;
    //Get all member variables of a class
    Ivar * ivars = class_copyIvarList([object class], &numIvars);
    //Define an array to receive the acquired property name
    NSMutableArray *nameArray = [[NSMutableArray alloc] initWithCapacity:numIvars];
    for(int i = 0; i < numIvars; i++) {
        //Get a single member variable
        Ivar thisIvar = ivars[i];
        //Get the type of this member variable
        const char *type = ivar_getTypeEncoding(thisIvar);
        NSString *stringType =  [NSString stringWithCString:type encoding:NSUTF8StringEncoding];
        //Skip when judging non object-c type here
        if (![stringType hasPrefix:@"@"]) {
            continue;
        }
        //Get member variable name
        NSString *variableName = [NSString stringWithUTF8String:ivar_getName(thisIvar)];
        [nameArray addObject:variableName];
        
        //This function can get the value of the member variable
        //object_getIvar(object, thisIvar)
        
    }
    free(ivars);
    return nameArray;
}

At this point, we create a Person class as shown in the figure

The results of calling these two methods are as follows