What is an expression?
An expression contains both operators and operands.
Example: a = b + c;
We can say, both “b + c” and “a = b + c” are expressions. Every expression will produce a result that can be assigned to a new operand.
In the above expression, we are performing the addition of b & c which will later be assigned to ‘a’.
- ‘+ =’ are operators.
- a, b, c are the operands.
- a = (b + c) is an expression.
Statement
There is a lot to explain about the statements. In simple terms, there is no C language without statements. Statements are a set of instructions that are executed in sequence and each of them has a predefined action and does not hold any values.
Labelled statement
If the statement is in the following format then it is known as a labelled statement.
Following is the syntax of labelled statements in the c language.
- Identifier: statement – It is mostly used as a target of goto.
- case constant-expression: statement
- default: statement
Please refer to the articles on goto & switch statements to get a clear idea of the labelled statements.
Expression statement
These are the most used statements in the C language. Expressions that end with a semicolon are known as expression statements. Most of the expression statements are assignment or function calls.
The result of one expression will be finalized before processing the expression of another statement.
Compound statement
A compound statement is also known as a block and it starts with ‘{‘ and ends with ‘}‘. One or more statements are combined together and formed as a single compound statement.
Syntax:
compound-statement:
{ declaration-list statement-list }
declaration-list:
declaration
declaration-list declaration
statement-list:
statement
statement-list statement
Selection statement
if, else, else if, switch statements are known as a selection statements.
Syntax
selection-statement:
if (expression) statement
if (expression) statement else statement
switch (expression) statement
Iteration statement
For, while, do while statements are known as the iteration statements
Syntax:
iteration-statement:
while (expression) statement
do statement while (expression);
for (expression; expression; expression) statement
Jump statement
Jump statements are used to transfer the control unconditionally.
goto, continue, break, and return statements are considered jump statements.
Syntax
jump-statement:
goto identifier;
continue;
break;
return expression;