Check Even Number in Python

What You’ll Learn

An even number is divisible by 2 with no remainder. This tutorial covers modulo and bitwise checks, zero and negatives, a live preview, worked Python examples, edge cases, and complexity.

📝 Problem & Approach

Given an integer n, decide whether it is even (divisible by 2).

# 10  → 10 % 2 == 0  → even
# 11  → 11 % 2 == 1  → odd
# 0   → even
# -4  → even

Inputs & Outputs

Minimal workflow

function is_even(n):
    return (n mod 2) == 0

function print_evens(start, end):
    for i from start to end:
        if is_even(i):
            output i

Method comparison

🔮 Live Preview

Works with positive and negative integers in JavaScript safe range.

Press "Check parity" to classify.

Examples Gallery

Three complete Python programs — modulo check, range scan, and bitwise parity. Click View Output to reveal sample console results.

def is_even(number: int) -> bool:
    return number % 2 == 0


number = 10
if is_even(number):
    print(f"{number} is an even number.")
else:
    print(f"{number} is not an even number.")

10 is an even number.

def is_even(num: int) -> bool:
    return num % 2 == 0


def print_evens_in_range(start: int, end: int) -> None:
    print(f"Even numbers in the range {start} to {end}:")
    for i in range(start, end + 1):
        if is_even(i):
            print(i, end=" ")


print_evens_in_range(1, 10)

Even numbers in the range 1 to 10:
2 4 6 8 10

def is_even_bitwise(number: int) -> bool:
    return (number & 1) == 0


for n in (10, 11, 0, -4):
    label = "even" if is_even_bitwise(n) else "odd"
    print(f"{n}: {label}")

10: even
11: odd
0: even
-4: even

🔎 Worked Walkthrough — n = 10

Trace the modulo method for a classic even value.

For contrast, 11 % 2 is 1 → odd.

⚖️ Facts Worth Knowing

Handy follow-ups interviewers sometimes ask.

🎯 Practice Problems

Try these variations to lock in the pattern.

Notes

⏱️ Time and Space Complexity

💡 Best Practices