Debugging

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jQuery Intermediate

Namespaced jQuery Events: The Teardown Trick Plugins Rely On

.off("click") nukes every click handler including ones you don't own. Namespaces let you unbind exactly your handlers - one suffix, surgical cleanup.

Apr 11, 2026 2 min 502 Read →

Y

PHP Intermediate

Your LIKE Search Has a Wildcard Injection Bug

Prepared statements stop SQL injection - but % and _ sail straight through into LIKE patterns, letting users dump whole tables or run pathological scans. The fix is three characters of escaping.

Mar 11, 2026 2 min 381 Read →

T

PHP Advanced

Turn PHP Warnings into Exceptions (and Catch Them Like an Adult)

Warnings scroll past in logs while your app continues in a corrupted state. One error handler converts them to catchable ErrorExceptions - and changes how you write file and network code.

Mar 4, 2026 2 min 503 Read →

Z

CSS Intermediate

z-index: 99999 Isn't Working Because of Stacking Contexts

When a dropdown hides behind a header despite a huge z-index, the number is not the problem - the element is trapped in a stacking context. Here is the mental model and the debugging routine.

Nov 15, 2025 3 min 969 Read →

:

CSS Beginner

:empty - Hide Containers That Have Nothing to Say

Notification badges showing "0", alert boxes rendering as empty bordered rectangles, list wrappers with padding and no list - :empty cleans up after your templates.

Oct 29, 2025 2 min 1,013 Read →

S

CSS Beginner

scrollbar-gutter: The Layout Shift You Blamed on Everything Else

Content jumps sideways when navigating between short and long pages because the scrollbar appears and steals width. One property reserves the space permanently.

Oct 13, 2025 2 min 1,401 Read →

C

CSS Advanced

Custom Property Patterns: Fallback Chains and the Invalid-Value Trap

CSS variables can chain fallbacks, expose component APIs and scope themes - and they fail in a uniquely confusing way that every serious user needs to understand once.

Sep 5, 2025 2 min 1,575 Read →

0

JavaScript Intermediate

0.1 + 0.2 Made Your Invoice Wrong: Money Math in JavaScript

Floating point cannot represent most decimal fractions, and prices are decimal fractions. Work in integer cents, round deliberately, and let Intl handle the display.

Jul 24, 2025 2 min 1,085 Read →

M

JavaScript Advanced

Measure Real User Performance with PerformanceObserver

Lighthouse tells you about your machine. PerformanceObserver tells you about your users - long tasks, slow interactions and layout shifts, from the field, in a few lines.

Apr 26, 2025 2 min 1,344 Read →

W

JavaScript Beginner

Why Your Click Handlers Die After AJAX (and the One-Line Fix)

Buttons work until the list refreshes over AJAX, then silently stop. Delegated events fix it permanently - and the same pattern is two lines in vanilla JS.

Nov 19, 2024 2 min 2,391 Read →

J

PHP Beginner

json_encode() Has Flags That Fix Its Worst Defaults

Escaped slashes, mangled unicode, silent failures returning false - json_encode ships with defaults from another era, and five flags fix all of it.

Nov 3, 2024 2 min 680 Read →

T

PHP Advanced

The PHP Session Lock That's Serializing Your AJAX Calls

Fire five parallel AJAX requests at a PHP backend and watch them execute one... at... a... time. The culprit is the session file lock, and the fix is a single function call.

Sep 5, 2024 2 min 682 Read →