Zero values in Go - Cheat Sheet & Quick Revision

Recall & Review

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What is a zero value in Go?

A zero value is the default value a variable has when it is declared but not explicitly initialized. It depends on the variable's type.

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What is the zero value of an int in Go?

The zero value of an int is 0.

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What is the zero value of a string in Go?

The zero value of a string is an empty string "".

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What is the zero value of a bool in Go?

The zero value of a bool is false.

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What is the zero value of a pointer type in Go?

The zero value of a pointer is nil, meaning it points to nothing.

What happens if you declare a variable in Go without assigning a value?

A It is automatically assigned 1.

B It causes a compile error.

C It contains random data.

D It gets the zero value of its type.

In Go, variables declared without explicit initialization get the zero value of their type.

What is the zero value of a float64 in Go?

A 1.0

B 0.0

C "" (empty string)

D nil

The zero value of float64 is 0.0.

Which of these is NOT a zero value in Go?

A "0" for string

B 0 for int

C nil for pointer

D false for bool

The zero value for string is an empty string "", not "0".

What is the zero value of a slice in Go?

A An empty slice with length 0

B A slice with one element 0

C nil

D A slice with random values

The zero value of a slice is nil, meaning it points to no underlying array.

Why are zero values useful in Go?

A They prevent variables from having garbage values.

B They make the program slower.

C They force you to always initialize variables.

D They cause runtime errors.

Zero values ensure variables have a safe default value, avoiding unpredictable behavior.

Explain what zero values are in Go and give three examples.

Think about what happens when you declare a variable without setting it.

Why does Go use zero values for uninitialized variables? How does this help programmers?

Consider how zero values affect program reliability.