A function is a block of code that executes when called, promotes code reusability, and allows parameter passing. The syntax includes specifying a return type, function name, and parameters. Functions enhance code readability and efficiency in execution.

1. Shahzadi Khan
ID:16262
Topic: Functions

2. function
DEFINITION:
• A Function is a block of code which only runs when it is
called
• Functions are important for reusing the code.
• You can pass parameters into the functions.

3. SYNTAX:
• returnType functionName() {
// Function body
}
• returnType functionName(parameterType1 parameterName1,
parameterType2 parameterName2, ...);
• returnType: Specifies the type of value the function will return (e.g., int,
void, float).
• functionName: The name used to call the function.
• parameterType: The data type of the parameter (e.g., int, float, string).
• parameterName: The name of the parameter (used within the function).

4. EXAMPLE:
void say() {
cout<<“Hello world”<<endl;
}
int main(){
say();
}
EXAMPLE 2:
void say(int num){
cout<<“hello world”<<num<<endl;
}
int main()
say(100);
}

5. Why we use function
• Code Reusability: Write code once and reuse it multiple times.
• It saves our time and make our execution fast.
• Improved Readability: Functions make the code more
understandable by giving descriptive names to specific tasks.

6. EXAMPLE:
void addition() {
Int a, b, sum;
cout<<“enter two numbers for addition:”<<endl;
cin>>a>>b;
Sum=a+b;
cout<<“addition:”<<sum<<endl;
}
int main(){
cout<<“first addition:”<<sum<<endl;
addition();
cout<<“second addition:”<<sum<<endl;
addition();
}