Objective-C Language Methods Pass by value parameter passing
Example
In pass by value of parameter passing to a method, actual parameter value is copied to formal parameter value. So actual parameter value will not change after returning from called function.
@interface SwapClass : NSObject
-(void) swap:(NSInteger)num1 andNum2:(NSInteger)num2;
@end
@implementation SwapClass
-(void) num:(NSInteger)num1 andNum2:(NSInteger)num2{
int temp;
temp = num1;
num1 = num2;
num2 = temp;
}
@end
Calling the methods:
NSInteger a = 10, b =20;
SwapClass *swap = [[SwapClass alloc]init];
NSLog(@"Before calling swap: a=%d,b=%d",a,b);
[swap num:a andNum2:b];
NSLog(@"After calling swap: a=%d,b=%d",a,b);
Output:
2016-07-30 23:55:41.870 Test[5214:81162] Before calling swap: a=10,b=20
2016-07-30 23:55:41.871 Test[5214:81162] After calling swap: a=10,b=20
