NSValue (any value can be packaged)

NSValue (any value can be packaged)

//// Main. m // OC05-task-05 // Created by Xin the Great on 15-1-26. // Copyright (c) 2015 Xin the Great. all rights reserved. // # import
 
  
Int main (int argc, const char * argv []) {@ autoreleasepool {// insert code here... ///////////////// /// NSValue can wrap any value of nsange range = {1, 5}; // wrap the struct into the object NSValue * value = [NSValue value: & range withObjCType: @ encode (nsange)]; NSLog (@ "value is % @", value); // restore the nsange newRange; [value getValue: & newRange]; // NSLog (@ "% ld, % ld", newRange. location, newRange. length); NSLog (@ "% @", NSStringFromRange (newRange )); ////////////////// ///// indicates an empty object NSNull * null = [NSNull null]; NSArray * arr = @ [@ "1", @ "2", null, @ "3"]; NSLog (@ "arr is % @", arr );} return 0 ;}