Passing values vs pointers in Go - Quick Revision & Key Differences

Recall & Review

beginner

What happens when you pass a value to a function in Go?

The function receives a copy of the value. Changes inside the function do not affect the original variable.

beginner

What is a pointer in Go?

A pointer holds the memory address of a variable, allowing functions to access and modify the original variable directly.

intermediate

How do you declare a pointer parameter in a Go function?

Use an asterisk (*) before the type in the function parameter, for example: func f(p *int) {}

intermediate

Why use pointers instead of passing values?

Pointers allow functions to modify the original data and can be more efficient for large data structures because they avoid copying.

beginner

What does the & operator do in Go?

It returns the memory address of a variable, creating a pointer to that variable.

What does passing a value to a function in Go do?

A Passes the variable name

B Passes the memory address

C Passes a reference to the value

D Passes a copy of the value

Passing a value sends a copy, so the original variable is not changed.

How do you pass a pointer to a function in Go?

A Use the & operator to get the address and * in the parameter

B Just pass the variable name

C Use the * operator to get the address

D Use the & operator in the parameter only

You use & to get the address when calling and * in the function parameter to receive the pointer.

What does the * operator do when used with a pointer in Go?

A Creates a new pointer

B Returns the address of the pointer

C Dereferences the pointer to access the value

D Copies the pointer value

The * operator accesses the value stored at the pointer's address.

Why might you prefer passing a pointer over a value?

A To make a copy of the variable

B To modify the original variable inside the function

C To avoid using memory

D To prevent changes to the variable

Passing a pointer lets the function change the original variable.

What happens if you change a value inside a function that received a copy?

A The original variable stays the same

B The original variable changes

C The program crashes

D The copy changes the original automatically

Changes to the copy do not affect the original variable.

Explain the difference between passing a value and passing a pointer to a function in Go.

Think about what happens inside the function when you change the parameter.

Describe how to declare and use a pointer parameter in a Go function.

Remember the & and * operators and their roles.