Ekene Agunechemba



👋 Hello, Code Explorer!

Today, let’s explore three powerful tools in JavaScript that help us find things in words or sentences:

  • .exec()
  • .test()
  • .match()

They all help you search, but they work in different ways — like different kinds of magnifying glasses! 🔍🔎🕵️

🧪 1. .test() – Ask “Is it there?”

.test() is super simple.

It only tells you true or false. That means: “Yes, it’s there” or “No, it’s not.”

Example:

var re = /cat/;
console.log(re.test("The cat is here"));  // true
console.log(re.test("No animal here"));   // false

✅ Use .test() when you just want to know if something matches.

📦 2. .exec() – Get All the Details

.exec() is like a detective. It doesn’t just say “yes”—it brings back:

  • What it found
  • Any captured parts
  • Where in the string it was found

Example:

var re = /c(at)/;
var result = re.exec("The cat is here");

console.log(result[0]);      // "cat" (whole match)
console.log(result[1]);      // "at" (captured group)
console.log(result.index);   // 4 (match starts at index 4)

✅ Use .exec() when you want extra info about the match.

🔁 3. .match() – Search Using the String

.match() is a lot like .exec(), but instead of calling it from the regex, you use it on the string.

Example:

var sentence = "The cat is here";
var result = sentence.match(/cat/);

console.log(result[0]); // "cat"

Want to find all matches? Add the g flag:

var str = "cat, bat, hat";
console.log(str.match(/at/g));  // ["at", "at", "at"]

✅ Use .match() when you want quick results, especially with multiple matches.

🧠 Summary Table

Goal Tool to Use What It Gives You
Just check if there’s a match .test() true or false
Get full match info and groups .exec() Array with full match + details
Find matches easily using a string .match() Match or array of matches

🧪 Review Practice – Try These!

  1. Which method only says “true” or “false”? A) .match() B) .exec() C) .test() D) .run()

  2. Which one gives you captured groups and index? A) .exec() B) .test() C) .find() D) .search()

  3. What will this return?

    /cat/.test("I have a dog.")

    A) true B) false C) “cat” D) null

  4. What does this return?

    "cat, bat, hat".match(/at/g)

    A) [“cat”, “bat”, “hat”] B) [“at”, “at”, “at”] C) “at” D) true

  5. In this code:

    var re = /d(o)g/;
var result = re.exec("My dog runs");

console.log(result[1]);

    What will it print?

    A) “dog” B) “d” C) “o” D) null

🎉 Great job learning about JavaScript’s matching tools!

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