Hi there, coding explorer!
Last week we learned about Variables & Data Types. Today, let’s move to the fun part — making decisions in code.
Concept of the Week: Operators + Conditionals
Operators: Tools to perform math or comparisons.
Conditionals: Let your program make choices based on conditions.
Analogy: A traffic light:
Green → go
Red → stop
Yellow → maybe go
Operators ask questions (is it green?
), conditionals act on the answer (if green → go
).
Tips:
Use meaningful variable names (
age
instead ofx
).Use the correct comparison operator (
==
vs=
).
Explanation in Plain English
Operators let you perform operations on values: math, comparisons, and logic.
Conditionals let your code decide what to do based on true/false conditions.
You can combine multiple conditions to make complex decisions.
Shorthand expressions like ternary operators let you write simple decisions in one line.
Tips:
Use meaningful variable names in your conditions (
age
instead ofx
).Always check the correct operator (
==
for comparison,=
for assignment).Keep nested conditions readable; use early returns or lookup tables if it gets too complex.
Use ternary operators for simple if-else logic.
Code Examples
# Python Example
age = 18
if age >= 18:
print("You can vote!")
else:
print("Not eligible yet")
// JavaScript Example
let age = 18;
if (age >= 18) {
console.log("You can vote!");
} else {
console.log("Not eligible yet");
}
Combining & Nesting
Multiple branches:
if → elif → else
(Python) /if → else if → else
(JS).Nested conditions: decisions inside decisions.
Ternary operator: shorthand for simple if-else statements.
Tips:
Combine conditions using
and / or
(Python) or&& / ||
(JS).Keep code readable; avoid deep nesting when possible.
Code Examples
# Python Example
age = 20
has_id = True
if age >= 18:
if has_id:
print("Entry allowed")
else:
print("ID required")
else:
print("Not allowed")
# Ternary
message = "Adult" if age >= 18 else "Minor"
print(message)
// JavaScript Example
let age = 20;
let hasID = true;
let message = (age >= 18) ? "Adult" : "Minor";
console.log(message);
Cleaner, Real-World Decisions
Avoid long if-else ladders; use lookup tables / dictionaries / objects.
Short-circuit logical operators save time (
if a and b
stops ifa
is False).Real-world uses: form validation, feature flags, decision trees.
Code Examples
# Python Example
grades = { 'A': "Excellent", 'B': "Good", 'C': "Average" }
letter = 'B'
print(grades.get(letter, "Fail"))
// JavaScript Example
const grades = { A: "Excellent", B: "Good", C: "Average" };
let letter = "B";
console.log(grades[letter] || "Fail");
AI Tip
Ask AI to explain conditional logic with real-life examples, and give small Python/JS snippets. It helps you understand logic, not just memorize code.
Mini Challenge
Check if a number is
"Even"
or"Odd"
.Create a grading system (
A, B, C, Fail
) using nested ifs and ternary operators.Build a login check:
Correct username + password →
"Welcome"
Username exists but wrong password →
"Wrong password"
Username not found →
"User not found"
Sign-off
That’s your second DSA Bite! Experiment with operators and conditionals this week — it’s the foundation for making your programs think and decide.
Next week: Loops and Functions 🔄 — repeat actions without writing the same line 100 times.