A.double B.char C.byte D.short
A.intc=a;a=b;b=c; B.a=a+b;?b=a-b;?a=a-b; C.intc=b;b=a;a=c; D.a=b;?b=a;
A.IfA≠BThenSystem.out.print("A不等于B"); B.If(A≠B)System.out.print("A不等于B"); C.If(A!=B)ThenSystem.out.print("A不等于B"); D.IfA!=BThenSystem.out.printf("A不等于B");