Job Ready Go

Lesson 10Working with Pointers

Go supports pointers. A pointer is a variable that stores the memory address of another variable where the data is stored, rather than storing a value itself. In this lesson, we will look at the use of pointers.

LEARNING OBJECTIVES

By the end of this lesson, you will be able to:

• Declare your own pointers.
• Dereference a pointer to view a value.
• Use a pointer to change the value of another variable.
• Compare pointers to determine if they are the same.
• Create an array of pointers and assign it values.
• Pass pointers to functions.

CREATING A POINTER

All variables in Go other than maps and slices are value types. What that means is that if you have a variable that you are passing to a function and you want to make changes to the variable outside of the function, you can't change the variable directly. A copy gets passed in whenever you send it to a function.

If you want to modify the variable, the general approach is to use a pointer to the memory address instead of trying to affect the variable itself. In other words, you can pass in a pointer to the address of the variable, rather than passing a copy of the value itself. When you pass in a pointer, both the original value and the value used in the function are pointing to the same part of memory. Because they're pointing to the same spot in memory, when you change one value, both variables are changed.

Pointers are also used to pass in larger variables. If you have a large struct, then your ...