For loop as while in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does a 'for' loop without initialization and post statements act like in Go?

It acts like a 'while' loop, running as long as the condition is true.

beginner

How do you write a 'while' loop in Go using a 'for' loop?

Use 'for' with only a condition, like: <br>

for condition {
    // code
}

intermediate

Why does Go not have a separate 'while' keyword?

Because the 'for' loop is flexible enough to act as a 'while' loop by omitting init and post statements.

beginner

Example: What will this Go code print?<br>

i := 0
for i < 3 {
    fmt.Println(i)
    i++
}

It will print:<br>0<br>1<br>2<br>Because the loop runs while i is less than 3, increasing i each time.

intermediate

Can you use 'break' and 'continue' inside a 'for' loop acting as a 'while' loop in Go?

Yes, 'break' stops the loop early, and 'continue' skips to the next iteration, just like in other loops.

In Go, how do you write a loop that behaves like a 'while' loop?

A repeat { /* code */ } until condition

B for condition { /* code */ }

C loop condition { /* code */ }

D while condition { /* code */ }

Go uses 'for' with only a condition to act like a 'while' loop. There is no 'while' keyword.

What happens if you write 'for {}' in Go?

A Loop runs once

B Syntax error

C Infinite loop

D Loop runs zero times

'for {}' is an infinite loop in Go because there is no condition to stop it.

Which part is missing in a 'for' loop acting as a 'while' loop?

A Initialization and post statements

B Condition

C Loop body

D Semicolon

A 'for' loop as 'while' omits initialization and post statements, keeping only the condition.

Can you use 'continue' inside a 'for' loop used as a 'while' loop in Go?

A Yes

B No

C Only with a label

D Only in Go 1.18+

'continue' works normally inside any 'for' loop in Go, including those acting as 'while' loops.

What will this code print?<br>i := 5<br>for i > 0 {<br> fmt.Println(i)<br> i--<br>}

A 0 1 2 3 4

B 1 2 3 4 5

C No output

D 5 4 3 2 1

The loop prints i while i is greater than 0, decreasing i each time from 5 down to 1.

Explain how to use a 'for' loop as a 'while' loop in Go and why Go uses this approach.

Think about what parts of a for loop you keep or remove to make it behave like while.

Write a Go code snippet that uses a 'for' loop as a 'while' loop to print numbers from 1 to 5.

Start with i=1, loop while i <= 5, print i, then increase i.