JavaScript If Else

Run code based on conditions.

✍️ 3 exercises + code challenge in this lesson

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Conditional statements run different code depending on a condition:

if (condition) { ... }
else if (otherCondition) { ... }
else { ... }

The ternary operator

A short form for simple choices: const label = age >= 18 ? "Adult" : "Minor";

Key Takeaways: JavaScript If Else

Mastering JavaScript If Else helps you write clean and reliable JavaScript code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.

JavaScript If Else Code Example

JavaScript

<input id="hour" type="number" min="0" max="23" value="14"> hour
<button onclick="check()">Greet</button>
<p id="out"></p>

<script>
  function check() {
    const h = Number(document.getElementById("hour").value);
    let greeting;

    if (h < 12) {
      greeting = "Good morning ☀️";
    } else if (h < 18) {
      greeting = "Good afternoon 🌤️";
    } else {
      greeting = "Good evening 🌙";
    }

    const type = h >= 9 && h < 17 ? "office hours" : "outside office hours";
    document.getElementById("out").textContent = `${greeting} (${type})`;
  }
  check();
</script>

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JavaScript If Else Practice Exercises

Check what you learned in “JavaScript If Else”.

/ 3 solved

Fill in the blank

Complete the condition.

 (age >= 18) {
  log("Adult");
}  {
  log("Minor");
}

✓ Correct! Not quite. Try again.

Multiple choice

Which is the ternary operator?

condition ? a : b condition => a : b if ? a a ?? b : c

✓ Correct! Not quite. Try again.

Code challenge

If marks is 50 or more, log "Pass", otherwise log "Fail".

Write the code in the live editor. Your answer is checked automatically.

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JavaScript If Else

The ternary operator

💡 Key Takeaways: JavaScript If Else

JavaScript If Else Code Example

JavaScript If Else Practice Exercises

Key Takeaways: JavaScript If Else