The return value type of a function in C defines the type of value returned after execution: Basic types: void (no return value), bool, integer, floating point, character reference type: type reference, type pointer structure or class : Type instance
The return value type of the function in C
The return value type of the function defines the value returned after the function is executed type.
Basic types
-
void
: Returns no value. -
bool
: Returns a Boolean value. - Integer type (
int
,short
,long
): Returns an integer. - Floating point type (
float
,double
): Returns a floating point number. - Character type (
char
): Returns a single character.
Reference type
-
T&
: Returns a reference to typeT
. -
T*
: Returns a pointer to typeT
.
struct and class
-
struct
orclass
name: Returns an instance of this type .
Practical case
Consider a function that calculates the sum of two numbers:
// 返回两个数字的和 int add(int a, int b) { return a + b; }
The return value type of this function isint
because it returns an integer.
Here's how to use this function:
int sum = add(10, 20); // sum 将包含 30
Other notes
- A function can have no return value type, in this case , they return
void
. - If a function does not explicitly specify a return value type, the compiler will default to
int
. - You can specify that the return value is a constant by using the
const
keyword.
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