slice, replace, split, trim, includes and more.
✍️ 3 exercises + code challenge in this lessonStrings come with many built-in methods. Strings are immutable: methods return a new string and never change the original.
toUpperCase(), toLowerCase()slice(start, end), substring()replace(), replaceAll()trim(): remove spaces at both endssplit(","): turn a string into an arrayincludes(), startsWith(), endsWith(), indexOf()padStart(), repeat(), at(-1)Mastering JavaScript String Methods 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.
<pre id="out"></pre>
<script>
const log = (...a) => document.getElementById("out").textContent += a.join(" ") + "\n";
const text = " Learn JavaScript at CodesInTech ";
const clean = text.trim();
log(clean.toUpperCase());
log(clean.slice(6, 16));
log(clean.replace("JavaScript", "Python"));
log(clean.includes("Code"), clean.startsWith("Learn"));
log("Last char:", clean.at(-1));
log("a,b,c".split(","));
log("7".padStart(3, "0"));
log("ha".repeat(3));
</script>Check what you learned in “JavaScript String Methods”.
Convert the text to upper case.
const loud = text.();
Which method removes spaces from both ends of a string?
Replace "cats" with "dogs" in the sentence and log the result.
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