C# Code Contracts: Array operations -

for university must learn how deal code contracts in c#.

i want use method should return smallest element in array:

public int minarray(int[] minarray) 

here got have no idea whether correct:

public int minarray(int[] minarray) {     //neither array should empty nor null     contract.requires(minarray != null && minarray.length != 0);     //save result...     int result = contract.result<int>();     //...and check:     contract.ensures(contract.forall(0, minarray.length, => minarray[i] >= result));  } 

can tell me if right or if wrote nonesense? i'd thankful.

beyond that, next task says:

public int[] posnegarray(int[] posneg) 

this should change sign of elements in method (e.g (1, -2,3) (-1,2, -3).

public int[] posnegarray(int[] posneg) {     //neither array should empty nor null     contract.requires(posneg != null && posneg.length != 0);     //save result...     int resarray = contract.result<int[]>();     //...and check:     contract.ensures(contract.forall(0, posneg.length, => posneg[i] == (-1) * resarray[i] ));       int[] returnarray = new int[posneg.length];     for(int j = 0; j < posneg.length; j++)       returnarray[j] = posneg[j] * (-1);     return returnarray; } 

can correct?

contract.result should used within contract.ensures method isn't executed represents result. way using execute method, return default (for int 0) , use default in ensures method isn't expecting. should put result method within ensures this:

contract.ensures(contract.result<int>() >= -1);