4, C # basic finishing (if statement classic exercises)

1, use if to determine whether the input is the space bar Method: (Console.readkey () the use of)

Consolekeyinfo Readkey = console.readkey (); Console.WriteLine (Readkey. Key.tostring ()); if " SPACEBAR " )         Console.WriteLine (" space ");

2, with If......else to determine whether it is a leap year (leap years to be divisible by 4, * Note: If the year can be divisible by 100, but also divisible by 400 is the leap)

Console.WriteLine ("Please enter the year:");intYear =int. Parse (Console.ReadLine ());if(Year%4==0){    if(Year% -==0)    {        if(Year% -==0) {Console.WriteLine ("Yes"); }        ElseConsole.WriteLine ("No"); }    ElseConsole.WriteLine ("Yes");}ElseConsole.WriteLine ("No");

3. If......else If......else Enter a number within a 1~100 to determine whether it is related to 7

Console.WriteLine ("Please enter a number within the 1~100");intShu =int. Parse (Console.ReadLine ());if(Shu >=1&& Shu <= -){    if(shu%Ten==7) Console.WriteLine ("Yes"); Else if(shu%7==0) Console.WriteLine ("Yes"); Else if(shu/Ten==7) Console.WriteLine ("Yes"); ElseConsole.WriteLine ("No");}Else{Console.WriteLine ("Input Error");}

4, input a,b,c, to find the solution of a two-time equation

Console.WriteLine ("Please enter A,b,c"); intA =int.            Parse (Console.ReadLine ()); intb =int.            Parse (Console.ReadLine ()); intc =int.            Parse (Console.ReadLine ()); if(A = =0&& B! =0)            {                Doublex = (Double) (-C)/b; Console.WriteLine ("There is a real roots {0}", x); }            Else if(A = =0&& b = =0) {Console.WriteLine ("A, B are zero, no real roots"); }            Else            {                DoubleDe =SQR (b * B-4Ac); if(De = =0)                {                    Doublex = (Double) (-B)/(2*a); Console.WriteLine ("There are two equal real roots, x1=x2={0}", x); }                Else if(De <0) {Console.WriteLine ("this equation has no solution"); }                Else                {                    DoubleX1 = (Double) ((-B) + math.sqrt (DE))/(2*a); Doublex2 = (Double) ((-B)-math.sqrt (DE))/(2*a); Console.WriteLine ("There are two real roots, x1={0},x2={1}", X1,X2); }            }            

4, C # basic finishing (if statement classic exercises)