C++ LANGUAGE LVALUES AND RVALUES PAGE 18

COMPUTER LANGUAGES HTML,C,C++.JAVA,.NET AND MULTIMEDIA basics and programs click home button

C++ LANGUAGE LVALUES AND RVALUES

Lvalues and Rvalues 


There are two kinds of expressions in C++: 

• lvalue : Expressions that refer to a memory location is called 
"lvalue" expression. An lvalue may appear as either the left-hand or 
right-hand side of an assignment. 

• rvalue : The term rvalue refers to a data value that is stored at 
some address in memory. An rvalue is an expression that cannot have 
a value assigned to it which means an rvalue may appear on the right- 
but not left-hand side of an assignment. 

Variables are lvalues and so may appear on the left-hand side of an 
assignment. Numeric literals are rvalues and so may not be assigned 
and cannot appear on the left-hand side. Following is a valid statement: 
int g = 20; 
But the following is not a valid statement and would generate compile-time error: 
10 = 20;