Loop execution flow in Go - Step-by-Step Execution

Concept Flow - Loop execution flow

Initialize loop variable i=0

↓

Check condition i < 3?

No→Exit loop

Yes↓

Execute loop body

↓

Update loop variable i = i + 1

↩Back to condition check

The loop starts by setting a variable, checks if it meets the condition, runs the loop body if yes, then updates the variable and repeats until the condition is false.

Execution Sample

Go

package main
import "fmt"
func main() {
  for i := 0; i < 3; i++ {
    fmt.Println(i)
  }
}

This Go program prints numbers 0, 1, and 2 using a for loop.

Execution Table

Step	i value	Condition (i < 3)	Action	Output
1	0	true	Print i=0	0
2	1	true	Print i=1	1
3	2	true	Print i=2	2
4	3	false	Exit loop

💡 Loop stops because i=3 is not less than 3 (condition false)

Variable Tracker

Variable	Start	After 1	After 2	After 3	Final
i	0	1	2	3	3

Key Moments - 2 Insights

Why does the loop stop when i equals 3?

Because the condition i < 3 becomes false at step 4 in the execution_table, so the loop exits.

When is the value of i updated in the loop?

After each loop body execution, i is increased by 1 as shown between steps in the variable_tracker.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of i when the loop condition becomes false?

A 3

B 2

C 0

D 1

💡 Hint

Check the last row of the execution_table where condition is false.

At which step does the loop print the number 1?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look at the Output column in execution_table for the printed values.

If the loop condition changed to i < 2, how many times would the loop run?

A 1 time

B 2 times

C 3 times

D 0 times

💡 Hint

Refer to variable_tracker and consider when the condition becomes false.

Concept Snapshot

Go for loop syntax:
for initialization; condition; post {
  // loop body
}

Loop runs while condition is true.
Variable updates happen after each iteration.
Loop stops when condition is false.

Full Transcript

This visual execution shows a Go for loop starting with i=0. Each step checks if i is less than 3. If yes, it prints i and then increases i by 1. This repeats until i reaches 3, when the condition fails and the loop stops. The variable tracker shows i changing from 0 to 3. Key moments clarify why the loop stops at 3 and when i updates. The quiz tests understanding of loop steps and condition changes.