I am starting to learn C and I am doing an assignment and this is part of the code I wrote:

if (2*b>9)
2*b = b   (b0-b)/10;

I am getting error: expression is not assignable and terminal is pointing at the "=" sign. can you tell me what is wrong here. Sorry if stupid question . Thanks

CodePudding user response：

2*b is an rvalue expression, so it can't be assigned. Instead you could assign the variable b to equal half the expression on the right, as below:

if (2*b>9)
    b = (b   (b0-b)/10)/2;

CodePudding user response：

Assigning the expression 2 * b is not possible (semantically it is not even clear what you might intend by that).

An assignment expression must be of the form: <lvalue> = <rvalue>.

An lvalue is an expression that represents an object that occupies some identifiable location in memory (i.e. has an address), That is one of a simple variable, an array subscript reference or a dereferenced pointer.

Note that all lvalues are also valid rvalues.