mBlock STEM Robotics Starter Course for Bekasi Students

1. Introduction to Type Conversion (Typecasting)

Type conversion (often referred to as typecasting) is the process of changing a value from one data type into another. For example:

• Converting an integer to a string if you need to apply string-based operations to it.
• Converting a string containing digits into an integer or float so that mathematical calculations can be performed.

Conversion	Example	Result
String to Integer	int("34")	34 (calculable)
String to Float	float("34.5")	34.5 (decimal)
Number to String	str(100)	"100" (text)

2. Converting Numeric Strings to Integers

When numerical data is enclosed in quotation marks (such as "34"), Python treats it strictly as text (str). To convert a numeric string into an integer, pass the variable into the built-in int() function:

age = "34"
print(type(age))
# Output: 

print(int(age) + 1)
# Output: 35

The same principle applies when converting text representations of decimals into floating-point numbers using float().

3. Getting User Input with the input() Function

Python provides the built-in input() function to prompt the user for keyboard data:

age = input("Please write your age: ")

When this line executes, Python displays the prompt and waits until the user types a response and presses Enter.

4. The Golden Rule of input(): Everything Arrives as a String

The input() function always returns user input in string (str) format—even if the user types digits like 71 or 25:

age = input("Please write your age: ")
# User enters: 71
print(type(age))
# Output: 

Because the value is stored as a string, you cannot immediately execute mathematical calculations with it.

5. Typecasting User Input for Computations

To perform calculations on numbers collected from the user, convert the string into an integer using int():

age = input("Please write your age: ")
my_age = int(age)
print(type(my_age))
# Output: 

next_year_age = my_age + 1
print("Next year you will be:", next_year_age)

Once converted, the program can execute any arithmetic operation without errors.

age = input("Please write your age: ")
my_age = int(age)
print(my_age + 1)