Else–if ladder in Go - Step-by-Step Execution

Concept Flow - Else–if ladder

Start

↓

Check if condition1

|Yes↓

Execute block1

↓

End

No↓

Check if condition2

|Yes↓

Execute block2

↓

End

No↓

Check if condition3

|Yes↓

Execute block3

↓

End

No↓

Execute else block

↓

End

The program checks conditions one by one from top to bottom. When a condition is true, it runs that block and skips the rest. If none are true, it runs the else block.

Execution Sample

Go

package main
import "fmt"
func main() {
  x := 15
  if x < 10 {
    fmt.Println("Less than 10")
  } else if x < 20 {
    fmt.Println("Between 10 and 19")
  } else {
    fmt.Println("20 or more")
  }
}

This code checks the value of x and prints which range it falls into using an else-if ladder.

Execution Table

Step	Condition Checked	Condition Result	Action Taken	Output
1	x < 10	False	Skip if block
2	x < 20	True	Execute else-if block	Between 10 and 19
3	Else block	Skipped	No action
4	End	N/A	Program ends

💡 Condition x < 20 is True, so else-if block runs and rest are skipped.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
x	15	15	15	15

Key Moments - 2 Insights

Why does the program skip the else block even though it exists?

Because the else-if condition (x < 20) was true at step 2, the program runs that block and skips the else block as shown in execution_table row 3.

What happens if the first condition is true?

If the first condition is true, the program executes that block and skips all else-if and else blocks, similar to how step 1 would show True and steps 2 and 3 would be skipped.

Visual Quiz - 3 Questions

Look at the execution table, what is the output at step 2?

A Between 10 and 19

B Less than 10

C 20 or more

D No output

💡 Hint

Check the 'Output' column at step 2 in the execution_table.

At which step does the program decide to skip the else block?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Action Taken' column for the else block in execution_table row 3.

If x was 5, how would the execution_table change at step 1?

A Condition Result would be True but no output

B Condition Result would be False and skip if block

C Condition Result would be True and output 'Less than 10'

D Condition Result would be False and output 'Between 10 and 19'

💡 Hint

Refer to variable_tracker and execution_table step 1 for condition x < 10.

Concept Snapshot

Else–if ladder syntax in Go:
if condition1 {
  // block1
} else if condition2 {
  // block2
} else {
  // else block
}

Checks conditions top-down, runs first true block, skips rest.
Else runs only if all conditions are false.

Full Transcript

This visual execution shows how an else-if ladder works in Go. The program checks each condition in order. If a condition is true, it runs that block and skips the rest. If none are true, it runs the else block. The example code checks if x is less than 10, then less than 20, else prints 20 or more. The execution table traces each step, showing conditions checked, results, actions, and output. Variable tracking shows x stays 15 throughout. Key moments clarify why else block is skipped and what happens if first condition is true. The quiz tests understanding of output and flow decisions. The snapshot summarizes the syntax and behavior simply.