What is diffrence between statement and expression in c?

Answer 1

well , in a rather simple way

an expression is a combination of of literals , variables , operators , functions calls which produces a particular value to be used in any other context

while a statement is an instruction to the computer telling it what to do for instance assigning an expression value to a variable , cause it produces an instructions tells the computer to assign a value to something.

to be more accurate , you can tell if A is a statement or an expression accurately by looking at the context which is been used in

well , in a rather simple way

an expression is a combination of of literals , variables , operators , functions calls which produces a particular value to be used in any other context

while a statement is an instruction to the computer telling it what to do for instance assigning an expression value to a variable , cause it produces an instructions tells the computer to assign a value to something.

to be more accurate , you can tell if A is a statement or an expression accurately by looking at the context which is been used in

Answer 2

It depends on the language in context/question.

The answer to this question is actually in that computer language specification. Every computer language has its own specification/definition of "expression" and "statement". There maybe some languages that do not even define what a statement is (no notion of statements, only expressions)

If you have 1 particular computer language in mind, it may break the concept below

In general:

• An EXPRESSION can be evaluated to a value.
• A statement does something.
• Same terms may not be in the same definition in 2 different languages

The evaluation of an expression may do something itself, like calling a function in an expression like:

100 * Call_A_SUB()

Call_A_SUB() is a function returns a value to be multiplied to 100. It may have done something (statements) before returning a final value!!

Answer 3

An expression can be a statement, but some statements aren't expressions. Examples for the former: x++, y = 3, printf ("Hello"); examples for the latter: if, else, while, for, do, switch, break, continue, return

Answer 4

Expressions can only be used as statements if you're using an assignment ("=") operator. Every statement must commit an action of some sort, whether it's modifying a variable or calling a function; so comparison expressions by themselves will do nothing. For instance, the following code is futile:

myvar==5;

You would need to use this within an 'if' statement at the very least:

if (myvar==5) { dosomething(); }

Or within a function:

doanotherthing(myvar==5);