If–else statement in Go - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if–else in Go

What is the output of this Go program?

Go

package main
import "fmt"
func main() {
  x := 10
  if x > 5 {
    if x < 15 {
      fmt.Println("A")
    } else {
      fmt.Println("B")
    }
  } else {
    fmt.Println("C")
  }
}

A A

B B

C C

D No output

💡 Hint

Check the conditions step by step from outer to inner if.

x is 10, which is greater than 5 and less than 15, so the inner if prints "A".

❓ Predict Output

intermediate

If–else with else if in Go

What will this Go program print?

Go

package main
import "fmt"
func main() {
  score := 75
  if score >= 90 {
    fmt.Println("Excellent")
  } else if score >= 60 {
    fmt.Println("Pass")
  } else {
    fmt.Println("Fail")
  }
}

A No output

B Excellent

C Fail

D Pass

💡 Hint

Check which condition matches the score 75.

75 is not >= 90 but is >= 60, so it prints "Pass".

❓ Predict Output

advanced

If–else with short statement and variable scope

What is the output of this Go code?

Go

package main
import "fmt"
func main() {
  if x := 5; x > 3 {
    fmt.Println(x)
  } else {
    fmt.Println("No")
  }
  // fmt.Println(x) // What if uncommented?
}

A Compilation error due to x scope

B No

C 5

D 0

💡 Hint

The variable x is declared in the if statement header.

x is 5 and greater than 3, so it prints 5. Outside the if block, x is not defined.

❓ Predict Output

advanced

If–else with multiple conditions

What does this Go program print?

Go

package main
import "fmt"
func main() {
  a, b := 3, 7
  if a > 5 && b < 10 {
    fmt.Println("X")
  } else if a > 2 || b > 10 {
    fmt.Println("Y")
  } else {
    fmt.Println("Z")
  }
}

A Y

B Z

C X

D No output

💡 Hint

Evaluate each condition carefully with given values.

a=3 > 2 is true, so the else if condition is true and prints "Y".

🧠 Conceptual

expert

Understanding if–else statement behavior in Go

Which statement about if–else statements in Go is TRUE?

A The condition in an if statement must always be enclosed in parentheses.

B The else keyword must always be on the same line as the closing brace of the if block.

C Go allows if statements without braces if there is only one statement inside.

D Variables declared in the if statement header are accessible outside the if–else blocks.

💡 Hint

Think about Go syntax rules for if–else formatting.

In Go, else must be on the same line as the closing brace of the if block; variables declared in if header are scoped to the if block; braces are mandatory; conditions are not enclosed in parentheses.

Practice

1. What does an if-else statement do in Go?

easy

A. It repeats code multiple times.

B. It declares a variable.

C. It defines a new function.

D. It chooses between two paths based on a condition.

Solution

1. Step 1: Understand the purpose of if-else

   An if-else statement checks a condition and runs code based on whether it is true or false.

2. Step 2: Compare with other options

   Repeating code is done by loops, functions define reusable code, and variables store data, so these are not correct.

3. Final Answer:

   It chooses between two paths based on a condition. -> Option D

4. Quick Check:

   If-else = choose path [OK]

Hint: If-else picks true or false path fast [OK]

Common Mistakes:

• Confusing if-else with loops
• Thinking if-else defines functions
• Mixing if-else with variable declaration

2. Which of these is the correct syntax for an if-else statement in Go?

easy

A. if x > 10 { fmt.Println("Big") } else { fmt.Println("Small") }

B. if (x > 10) then { fmt.Println("Big") } else { fmt.Println("Small") }

C. if x > 10: fmt.Println("Big") else: fmt.Println("Small")

D. if x > 10 { fmt.Println("Big") } elseif { fmt.Println("Small") }

Solution

1. Step 1: Check Go if-else syntax

   Go uses braces {} for blocks and no parentheses or colons around conditions.

2. Step 2: Identify correct syntax

   if x > 10 { fmt.Println("Big") } else { fmt.Println("Small") } matches Go syntax exactly. Options A, B, and D use wrong keywords or punctuation.

3. Final Answer:

   if x > 10 { fmt.Println("Big") } else { fmt.Println("Small") } -> Option A

4. Quick Check:

   Go if-else uses braces {} [OK]

Hint: Remember: Go uses braces, no then or colons [OK]

Common Mistakes:

• Using 'then' keyword
• Adding colons after conditions
• Writing 'elseif' instead of 'else if'

3. What will this Go code print?

package main
import "fmt"
func main() {
  x := 5
  if x > 10 {
    fmt.Println("Greater")
  } else {
    fmt.Println("Smaller or equal")
  }
}

medium

A. Greater

B. Smaller or equal

C. 5

D. No output

Solution

1. Step 1: Check the value of x

   x is assigned 5, which is not greater than 10.

2. Step 2: Follow the if-else logic

   Since x > 10 is false, the else block runs, printing "Smaller or equal".

3. Final Answer:

   Smaller or equal -> Option B

4. Quick Check:

   5 > 10? No, print else [OK]

Hint: Check condition truth, then pick output [OK]

Common Mistakes:

• Assuming 5 is greater than 10
• Confusing if and else blocks
• Expecting variable value as output

4. Find the error in this Go code:

package main
import "fmt"
func main() {
  x := 7
  if x > 5
    fmt.Println("Big")
  else
    fmt.Println("Small")
}

medium

A. Missing braces {} around if and else blocks

B. Wrong import statement

C. Variable x not declared

D. Missing semicolon after if condition

Solution

1. Step 1: Check if-else block syntax

   In Go, if and else blocks must use braces {} to group statements.

2. Step 2: Identify missing braces

   The code lacks braces around the print statements, causing a syntax error.

3. Final Answer:

   Missing braces {} around if and else blocks -> Option A

4. Quick Check:

   Go requires braces for blocks [OK]

Hint: Always use braces {} for if and else blocks [OK]

Common Mistakes:

• Omitting braces in if-else
• Thinking semicolons are needed after conditions
• Confusing import errors with syntax errors

5. You want to print "Even" if a number is even, otherwise print "Odd". Which Go code correctly does this?

hard

A. if num % 2 = 0 { fmt.Println("Even") } else { fmt.Println("Odd") }

B. if num / 2 == 0 { fmt.Println("Even") } else { fmt.Println("Odd") }

C. if num % 2 == 0 { fmt.Println("Even") } else { fmt.Println("Odd") }

D. if num % 2 != 0 { fmt.Println("Even") } else { fmt.Println("Odd") }

Solution

1. Step 1: Understand how to check even numbers

   A number is even if remainder when divided by 2 is zero (num % 2 == 0).

2. Step 2: Check each option's condition

   if num % 2 == 0 { fmt.Println("Even") } else { fmt.Println("Odd") } uses correct equality check. if num / 2 == 0 { fmt.Println("Even") } else { fmt.Println("Odd") } divides instead of modulo. if num % 2 = 0 { fmt.Println("Even") } else { fmt.Println("Odd") } uses assignment (=) instead of comparison (==). if num % 2 != 0 { fmt.Println("Even") } else { fmt.Println("Odd") } reverses logic.

3. Final Answer:

   if num % 2 == 0 { fmt.Println("Even") } else { fmt.Println("Odd") } -> Option C

4. Quick Check:

   Modulo equals zero means even [OK]

Hint: Use modulo % and == 0 to check even [OK]

Common Mistakes:

• Using / instead of %
• Using = instead of ==
• Reversing condition logic