3.7-P2 Nested Conditionals

Nested conditionals and what are they?

• Conditional Statements: A conditional statement in programming is a way to make decisions. It checks if something is true or false, and based on that, it tells the program what to do next.
• Nested Conditionals: A nested conditional in coding is when an if or else statement is placed inside another if or else statement. This allows for checking multiple conditions in sequence

Example #1: Drivers license

Python

age = int(input("Enter your age: "))
has_license = input("Do you have a driver's license? (yes/no): ").lower()

if age >= 16:
    if has_license == "yes":
        print("You can drive!")
    else:
        print("Get a driver's license.")
else:
    print("Not old enough to drive.")

Not old enough to drive.

Javascript

%%js
// Get user input
let age = parseInt(prompt("Enter your age: "));
let hasLicense = prompt("Do you have a driver's license? (yes/no): ").toLowerCase();

// Check if the person can drive
if (age >= 16) {
    if (hasLicense === "yes") {
        console.log("You can drive!");
    } else {
        console.log("Get a driver's license.");
    }
} else {
    console.log("Not old enough to drive.");
}

<IPython.core.display.Javascript object>

• User Input: The code prompts the user to enter their age and whether they have a driver’s license, storing the values in age and hasLicense.
• Age Check: It first checks if the user is 18 years old or older. If true, it proceeds to check if they have a driver’s license.
• License Check: Depending on whether they have a license, the code outputs either “You can drive!” or “Get a driver’s license.” If the user is under 18, it outputs “Not old enough to drive.”

Example #2: Credit Score

Python

credit_score = 100
income = 10000

if credit_score < 700:
    print("Not eligible for loan due to low credit score")
elif income < 50000:
    print("Not eligible for loan due to low income")
else:
    print("Eligible for loan")

Not eligible for loan due to low credit score

Javascript

%%js
let credit_score = 100;
let income = 10000;

if (credit_score < 700) {
    console.log("Not eligible for loan due to low credit score");
} else if (income < 50000) {
    console.log("Not eligible for loan due to low income");
} else {
    console.log("Eligible for loan");
}

<IPython.core.display.Javascript object>

• Both snippets (Python and JavaScript) check loan eligibility based on two factors: credit_score and income.
• If the credit_score is less than 700, both codes print a message stating that the person is not eligible due to a low credit score.
• If the credit_score is 700 or higher but the income is less than 50,000, both codes output that the person is not eligible due to low income.
• If both conditions are met (credit score ≥ 700 and income ≥ 50,000), both snippets print that the person is eligible for a loan.
• The Python code uses print() to display messages in the console, while the JavaScript code uses console.log() to achieve the same result.

Example #3 : Shipping

is_subscriber = True
order_weight = 12

if is_subscriber:
    if order_weight > 10:
        print("Free express shipping")
    else:
        print("Free standard shipping")
else:
    if order_weight > 10:
        print("Free standard shipping")
    else:
        print("No free shipping")

Free express shipping

• The code checks if a person is a subscriber using the is_subscriber variable.
• If they are a subscriber and the order_weight is greater than 10, it prints “Free express shipping.”
• If they are a subscriber and the weight is 10 or less, it prints “Free standard shipping.”
• If they are not a subscriber, it checks the weight again and either prints “Free standard shipping” or “No free shipping” based on the weight.

Summary of Nested Conditionals and Conditional Statements

• Conditional Statements*: Conditional statements are programming structures that run specific code based on whether a condition is true or false. The most common type is the if statement, which can be followed by else or else if to manage different outcomes.
• Nested Conditionals*: Nested conditionals are when one conditional statement is placed inside another, allowing you to check extra conditions based on earlier ones, which helps your program make more complex decisions.