Program 6-2: Program to print the positive difference of two numbers.

Question

Accepted Answer

> [!TLDR]
> Fix Program 6-1's negative result with two-way selection: if num1 > num2 subtract num2 from num1, else subtract the other way — the difference is now always non-negative.

**The idea.** Program 6-1 printed -5 for inputs 5 and 10 because it always computed num1 - num2. To report the **positive** difference we must *decide at run time* which number to subtract from which — the chapter's first real use of the **if–else** construct: one condition, two alternative computations, exactly one of which executes.

**Program**

```python
num1 = int(input("Enter first number: "))
num2 = int(input("Enter second number: "))

if num1 > num2:
    diff = num1 - num2
else:
    diff = num2 - num1

print("The positive difference of", num1, "and", num2, "is", diff)
```

**Sample runs**

```text
Enter first number: 10
Enter second number: 5
The positive difference of 10 and 5 is 5
```

```text
Enter first number: 5
Enter second number: 10
The positive difference of 5 and 10 is 5
```

Both input orders now give the same answer, 5 — the branch taken differs, the result does not.

**Trace**

| num1 | num2 | num1 > num2? | Branch | diff |
| --- | --- | --- | --- | --- |
| 10 | 5 | True | if | 10 - 5 = 5 | …

Q.Program 6-2: Program to print the positive difference of two numbers.

Concept understanding — Variable Difference

Variable Difference — The Intuition

The Precise Statement

Why This Matters

Q.Program 6-2: Program to print the positive difference of two numbers.

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