0x20Lesson 3 of 6

Make decisions with if

Choose different behavior based on a condition.

14 min 4-question quiz 1 code exercise

By the end of this lesson you can

Use if and else to select a result.

An if statement runs a block only when its condition is true. Add else for the other path. Go does not wrap conditions in parentheses, but braces are required. A short variable declaration can appear before the condition.

main.go

1package main
2
3import "fmt"
4
5func main() {
6    score := 82
7    if score >= 60 {
8        fmt.Println("pass")
9    } else {
10        fmt.Println("try again")
11    }
12}

Output

pass

Conditions evaluate to a bool. Comparison operators include ==, !=, <, <=, >, and >=. Keep the else attached to the closing brace of the if block.

Key takeaways

Use if and else to select a result.
Go catches many mistakes while compiling.
Use small experiments to understand each new language feature.

Lesson quiz

4 questions · pass with 3 correct · up to 50 XP

Passing this quiz completes the lesson and keeps your streak going. Questions you miss come back in review sessions later.

Practice: write Go

Write Go in the editor and run it against sample input with a remote compiler. Your code is sent to Compiler Explorer to compile and run.

Exercise 1

Label a temperature

+25 XP

Read an integer temperature. Print cold if it is below 15; otherwise print warm.

Below threshold
At threshold

main.go

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Go is compiled and run by Compiler Explorer (godbolt.org), a free public service. Your source code and test input are sent to that service.

Questions about this lesson

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