L-value 和 R-value.

标签：des   style   blog   color   strong   cti   

　　An L-value is something that can appear on the left side of an equal sign, An R-value is something that can appear on the right side of an equal sign.

　　for example:

1 a = b + 25;

‘a‘ is an L-value because it identifies a place where a result can be stored.

‘b + 25‘ is an R-value because it designates a value.

　　It sounds as though variable may be used as L-value but expressions may not, but this statement is not quite accurate,for example:

1 int a[3];
2 a[b + 1] = 0;

　　Subscripting is in fact an operator so the construct on the left is an expression, yet it is a legitimate L-value because it identifies a specific location that we can refer to later in the program.

　　Some operators, like indirection and subscripting, produce an L-value as a result.

L-value 和 R-value.,布布扣,bubuko.com

L-value 和 R-value.

标签：des   style   blog   color   strong   cti   

原文地址：http://www.cnblogs.com/listened/p/3819148.html