procedure Inc(var X [ ; N: Longint ] );DescriptionIn Delphi code, Inc adds one or N to the variable X.X is a variable of an ordinal type (including Int64), or a pointer type if the extended syntax is enabled.N is an integer-type expression. X increments by 1, or by N if N is specified; that is, Inc(X) corresponds to the statement X := X + 1, and Inc(X, N) corresponds to the statement X := X + N. However, Inc generates optimized code and is especially useful in tight loops.Note: If X is a pointer type, it increments X by N times the size of the type pointed to. Thus, giventype PMytype = ^TMyType;andvar P: PMyType;the statementInc(P);increments P by SizeOf(TMyType).Warning: You can抰 use Inc on properties because it modifies the parameter.Note: Inc(S, I) where S is a ShortInt and I is a number greater than 127 will cause an EIntOverFlow exception to be raised if range and overflow checking are on. In Delphi 1.0, this did not raise an exception.
Dec() --可以传递一个或两个参数
Inc(variable,N); (N表示递增或递减值的大小)
N 是一个整型表达式. X 增加1,如果指定了n就增加n; 也就是说, Inc(X) 相当于语句X := X + 1, 并且 Inc(X, N) 也相当于语句X := X + N.但是, Inc 优化了代码,执行效率更高.注意:如果X是指针类型, 他将增加X所指的数据的N倍大小. 因此:type PMytype = ^TMyType;andvar P: PMyType;the statementInc(P);increments P by SizeOf(TMyType).警告: 你可以在属性中用此函数因为他可以修改参数.注意: Inc(S, I) 中如果S超出了他的最大值,将要引起错误
inc(i,3)--->i:=i+3;
dec(i) --->i:=i-1;
dec(i,3)--->i:=i-3;
OK!
既然你问了,我就大发善心的告诉你啦!
INC(i)就是C中的 i++;