Array declaration in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an array in Go?

An array in Go is a fixed-size collection of elements of the same type stored in contiguous memory locations.

beginner

How do you declare an array of 5 integers in Go?

You declare it like this: var arr [5]int. This creates an array named arr that can hold 5 integers.

intermediate

What happens if you try to assign more elements than the declared size of an array in Go?

You will get a compile-time error because arrays have fixed size and cannot hold more elements than declared.

beginner

How can you declare and initialize an array in one line in Go?

You can write: arr := [3]int{10, 20, 30}. This creates an array of size 3 with values 10, 20, and 30.

intermediate

What is the difference between an array and a slice in Go?

An array has a fixed size known at compile time, while a slice is a flexible, dynamic view over an array that can grow or shrink.

How do you declare an array of 4 strings in Go?

A arr := [4]string{}

B var arr [4]string

C arr := make([]string, 4)

D var arr []string

Option B declares a fixed-size array of 4 strings. Option D and C declare slices, not arrays. Option A is invalid syntax.

What is the default value of elements in a newly declared integer array in Go?

A undefined

B nil

C 0

D empty string

Integer arrays are initialized with zero values, so each element is 0 by default.

Which of these is a valid way to declare and initialize an array in Go?

A arr := []int{1, 2, 3}

B arr := array{1, 2, 3}

C var arr = [3]int(1, 2, 3)

D arr := [3]int{1, 2, 3}

Option D correctly declares and initializes an array. Option A is a slice. Options C and D are invalid syntax.

What happens if you try to access an index outside the declared size of an array in Go?

A Runtime panic

B Compile-time error

C Returns zero value

D Returns last element

Accessing out-of-range index causes a runtime panic in Go.

Which statement about Go arrays is true?

A Arrays have fixed size and hold elements of the same type.

B Arrays hold elements of different types.

C Arrays can change size after declaration.

D Arrays are pointers to slices.

Arrays in Go have fixed size and all elements must be of the same type.

Explain how to declare and initialize an array in Go with examples.

Think about using var and shorthand := with curly braces.

Describe the difference between arrays and slices in Go.

Consider how flexible each type is and how they relate.