String to Integer atoi in DSA Python - Build from Scratch

String to Integer atoi

📖 Scenario: Imagine you are building a simple calculator app. Users type numbers as text, but your app needs to convert these text numbers into actual numbers to do math.

🎯 Goal: Build a small program that converts a string containing a number into an integer number, just like the atoi function does.

📋 What You'll Learn

Create a string variable with a number in text form

Create a variable to hold the converted integer

Write code to convert the string to an integer

Print the integer to see the result

💡 Why This Matters

🌍 Real World

Converting text input from users into numbers is common in calculators, forms, and data processing apps.

💼 Career

Understanding how to convert strings to numbers is a basic skill for software developers working with user input and data parsing.

1

Create the string number

Create a string variable called num_str and set it to the exact value "1234".

DSA Python

# Create a string variable called num_str with value "1234"
# Your code here

Hint

Use quotes to create a string. For example: num_str = "1234"

2

Prepare the integer variable

Create a variable called num_int and set it to 0. This will hold the converted number.

DSA Python

num_str = "1234"
# Create a variable num_int and set it to 0
# Your code here

Hint

Just write num_int = 0 to start with zero.

3

Convert the string to integer

Use the built-in int() function to convert num_str to an integer and assign it to num_int.

DSA Python

num_str = "1234"
num_int = 0
# Convert num_str to integer and store in num_int
# Your code here

Hint

Use num_int = int(num_str) to convert the string to a number.

4

Print the integer result

Print the value of num_int using print(num_int) to see the converted number.

DSA Python

num_str = "1234"
num_int = 0
num_int = int(num_str)
# Print num_int
# Your code here

Hint

Use print(num_int) to show the number on screen.