If statement in Go - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if statements

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("Inside nested if")
        }
    } else {
        fmt.Println("Outside if")
    }
}

A No output

B Outside if

C Inside nested if

D Compilation error

💡 Hint

Check the conditions in the nested if statements carefully.

The variable x is 10, which is greater than 5 and less than 15, so the nested if condition is true and prints "Inside nested if".

❓ Predict Output

intermediate

If statement with else if

What will this Go program print?

Go

package main
import "fmt"
func main() {
    score := 75
    if score >= 90 {
        fmt.Println("Grade A")
    } else if score >= 80 {
        fmt.Println("Grade B")
    } else if score >= 70 {
        fmt.Println("Grade C")
    } else {
        fmt.Println("Grade F")
    }
}

A Grade A

B Grade C

C Grade B

D Grade F

💡 Hint

Check which condition matches the score value first.

The score is 75, which is not >= 90 or >= 80 but is >= 70, so it prints "Grade C".

❓ Predict Output

advanced

If statement with short statement

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")
    }
}

A 0

B No

C Compilation error: x undefined

D 5

💡 Hint

Look at how the variable x is declared inside the if statement.

The variable x is declared and initialized to 5 in the if statement. Since 5 > 3 is true, it prints 5.

❓ Predict Output

advanced

If statement with multiple conditions

What will this Go program output?

Go

package main
import "fmt"
func main() {
    a, b := 4, 7
    if a > 3 && b < 10 {
        fmt.Println("Condition met")
    } else {
        fmt.Println("Condition not met")
    }
}

A Condition met

B Condition not met

C Compilation error

D No output

💡 Hint

Both conditions must be true for the if block to run.

a is 4 which is > 3 and b is 7 which is < 10, so both conditions are true and it prints "Condition met".

❓ Predict Output

expert

If statement with variable shadowing

What is the output of this Go program?

Go

package main
import "fmt"
func main() {
    x := 10
    if x := 5; x > 3 {
        fmt.Println(x)
    }
    fmt.Println(x)
}

A 5\n10

B 10\n10

C 5\n5

D Compilation error

💡 Hint

Notice the variable x declared inside the if statement shadows the outer x.

Inside the if statement, x is 5 and prints 5. Outside, the original x is still 10 and prints 10.

Practice

1. What does an if statement do in Go?

easy

A. It runs code only if a condition is true.

B. It repeats code multiple times.

C. It stores data in a variable.

D. It defines a new function.

Solution

1. Step 1: Understand the purpose of an if statement

   An if statement checks a condition and runs code only when that condition is true.

2. Step 2: Compare options with the if statement behavior

   Only "It runs code only if a condition is true." describes running code based on a condition being true.

3. Final Answer:

   It runs code only if a condition is true. -> Option A

4. Quick Check:

   If statement = runs code if true [OK]

Hint: If checks true/false to decide running code [OK]

Common Mistakes:

• Confusing if with loops
• Thinking if stores data
• Mixing if with function definitions

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

easy

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

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

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

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

Solution

1. Step 1: Recall Go if statement syntax

   Go uses if condition { code } without parentheses or 'then'.

2. Step 2: Check each option

   if x > 10 { fmt.Println("Big") } matches Go syntax exactly. Options A, C, and D have syntax errors.

3. Final Answer:

   if x > 10 { fmt.Println("Big") } -> Option B

4. Quick Check:

   Go if syntax = if condition { } [OK]

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

Common Mistakes:

• Adding 'then' keyword
• Using parentheses around condition
• Using colon instead of braces

3. What is the output of this Go code?

package main
import "fmt"
func main() {
  x := 5
  if x > 3 {
    fmt.Println("Yes")
  } else {
    fmt.Println("No")
  }
}

medium

A. Syntax error

B. No

C. 5

D. Yes

Solution

1. Step 1: Check the condition in the if statement

   The variable x is 5, and the condition is x > 3, which is true.

2. Step 2: Determine which block runs

   Since the condition is true, the code inside the if block runs, printing "Yes".

3. Final Answer:

   Yes -> Option D

4. Quick Check:

   x=5 > 3 is true, prints "Yes" [OK]

Hint: If condition true runs if-block, else runs else-block [OK]

Common Mistakes:

• Confusing which block runs
• Thinking it prints the variable
• Assuming syntax error due to else

4. Find the error in this Go code:

package main
import "fmt"
func main() {
  x := 10
  if x > 5
    fmt.Println("Big")
}

medium

A. Variable x not declared

B. Missing semicolon after x := 10

C. Missing braces { } after if condition

D. Wrong import statement

Solution

1. Step 1: Check if statement syntax

   In Go, the if condition must be followed by braces { } to group the code.

2. Step 2: Identify the missing part

   The code after if lacks braces, causing a syntax error.

3. Final Answer:

   Missing braces { } after if condition -> Option C

4. Quick Check:

   If needs braces { } after condition [OK]

Hint: Always use braces { } after if condition [OK]

Common Mistakes:

• Omitting braces after if
• Adding unnecessary semicolons
• Misunderstanding import errors

5. You want to print "Positive", "Zero", or "Negative" based on an integer variable n. Which code correctly uses if statements to do this?

hard

A. if n > 0 { fmt.Println("Positive") } else if n == 0 { fmt.Println("Zero") } else { fmt.Println("Negative") }

B. if n > 0 { fmt.Println("Positive") } if n == 0 { fmt.Println("Zero") } else { fmt.Println("Negative") }

C. if n > 0 { fmt.Println("Positive") } else if n <= 0 { fmt.Println("Negative") } else { fmt.Println("Zero") }

D. if n >= 0 { fmt.Println("Positive") } else if n == 0 { fmt.Println("Zero") } else { fmt.Println("Negative") }

Solution

1. Step 1: Understand the conditions for each case

   Positive means n > 0, zero means n == 0, negative means n < 0.

2. Step 2: Check each option's logic

   if n > 0 { fmt.Println("Positive") } else if n == 0 { fmt.Println("Zero") } else { fmt.Println("Negative") } correctly checks n > 0, then n == 0, else negative. if n > 0 { fmt.Println("Positive") } if n == 0 { fmt.Println("Zero") } else { fmt.Println("Negative") } has two separate ifs causing multiple prints. if n > 0 { fmt.Println("Positive") } else if n <= 0 { fmt.Println("Negative") } else { fmt.Println("Zero") } swaps zero and negative logic. if n >= 0 { fmt.Println("Positive") } else if n == 0 { fmt.Println("Zero") } else { fmt.Println("Negative") } wrongly treats n >= 0 as positive.

3. Final Answer:

   if n > 0 { fmt.Println("Positive") } else if n == 0 { fmt.Println("Zero") } else { fmt.Println("Negative") } -> Option A

4. Quick Check:

   Correct if-else chain matches conditions [OK]

Hint: Use else if to check exclusive conditions in order [OK]

Common Mistakes:

• Using multiple ifs causing multiple outputs
• Mixing condition order
• Wrong comparison operators