Script SpringsISSUE #13 of 29

string methods · slice · split · replace

SparkyVSNaN the Trickster

Sparky saysString methods: slice, split, replace/replaceAll, includes, trim, toUpperCase, padStart.

The toolkit: slice(start,end) extracts; split(sep) makes an array; replace/replaceAll substitute; includes/startsWith/endsWith test; trim removes edge whitespace; padStart/padEnd pad. All return new strings (immutable).

Power-ups you unlock

slice/substring extract; split → array
replace / replaceAll substitute
includes/startsWith/endsWith test
trim, padStart/padEnd, toUpperCase

NaN the Trickster attacks — common mistakes

replace only swaps the first match (use replaceAll/global regex)
Confusing slice (supports negatives) with substring
Expecting methods to mutate the original

Boss battleTake a messy string, trim it, uppercase it, and replace all spaces with dashes.

Example code

<!doctype html><html><head><meta charset="utf-8"></head>
<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre id="o"></pre>
<script>const s='  hello world  ';
document.getElementById('o').textContent = s.trim().toUpperCase().replaceAll(' ','-');</script></body></html>

▶ Open the interactive comic issue

‹ Template Literals · Interpolation Booleans · Truthy · Falsy ›