Basic data types in Go - Step-by-Step Execution

Concept Flow - Basic data types

Start

↓

Declare variable with type

↓

Assign value matching type

↓

Use variable in code

↓

Program runs with correct types

↓

End

This flow shows how Go variables are declared with specific types, assigned values, and used in the program.

Execution Sample

Go

package main
import "fmt"
func main() {
  var age int
  age = 30
  var name string
  name = "Alice"
  fmt.Println(name, age)
}

This code declares variables of basic types int and string, assigns values, and prints them.

Execution Table

Step	Action	Variable	Type	Value	Output
1	Declare variable	age	int	0 (default)
2	Assign value	age	int	30
3	Declare variable	name	string	"" (default)
4	Assign value	name	string	"Alice"
5	Print variables	name, age	string, int	"Alice", 30	Alice 30
6	Program ends

💡 Program ends after printing variables with assigned values.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
age	undefined	0	30	30	30	30
name	undefined	undefined	undefined	""	"Alice"	"Alice"

Key Moments - 3 Insights

Why does 'age' start with 0 before assignment?

In Go, variables declared with a type get a default zero value (0 for int) before explicit assignment, as shown in step 1 of the execution_table.

Can we assign a string value to 'age' variable?

No, because 'age' is declared as int type. Assigning a string would cause a compile error. The execution_table shows 'age' only holds int values.

Why do we need to declare variable types explicitly?

Go is statically typed, so variable types must be declared to ensure type safety. This is shown in the declaration steps in the execution_table.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of 'name' after step 4?

A ""

B "Alice"

C undefined

D 30

💡 Hint

Check the 'Value' column for 'name' at step 4 in the execution_table.

At which step does 'age' get assigned the value 30?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look at the 'Action' and 'Value' columns for 'age' in the execution_table.

If we tried to assign a string to 'age', what would happen?

A Compile error due to type mismatch

B Program prints the string

C Variable 'age' changes type to string

D Program runs but value ignored

💡 Hint

Recall Go's static typing explained in key_moments and the variable types in execution_table.

Concept Snapshot

Basic data types in Go:
- Declare variables with 'var name type'
- Types include int, string, bool, etc.
- Variables get default zero values
- Assign values matching declared type
- Type safety prevents mismatched assignments

Full Transcript

This example shows how Go handles basic data types. Variables are declared with a type, like int or string. When declared, they get default zero values (0 for int, empty string for string). Then we assign actual values. The program prints these values. Go checks types strictly, so you cannot assign a string to an int variable. This ensures your program runs safely and predictably.