Nicholai
75168f7678
structure: state/CURRENT.md — 2-4 line session state (rewritten each session) events/ — json event bus (pull-based, optional context) persistent/ — important decisions (one doc per decision) emit — helper script for emitting events
41 lines
980 B
Markdown
41 lines
980 B
Markdown
---
|
|
title: Use Explicit Conditional Rendering
|
|
impact: LOW
|
|
impactDescription: prevents rendering 0 or NaN
|
|
tags: rendering, conditional, jsx, falsy-values
|
|
---
|
|
|
|
## Use Explicit Conditional Rendering
|
|
|
|
Use explicit ternary operators (`? :`) instead of `&&` for conditional rendering when the condition can be `0`, `NaN`, or other falsy values that render.
|
|
|
|
**Incorrect (renders "0" when count is 0):**
|
|
|
|
```tsx
|
|
function Badge({ count }: { count: number }) {
|
|
return (
|
|
<div>
|
|
{count && <span className="badge">{count}</span>}
|
|
</div>
|
|
)
|
|
}
|
|
|
|
// When count = 0, renders: <div>0</div>
|
|
// When count = 5, renders: <div><span class="badge">5</span></div>
|
|
```
|
|
|
|
**Correct (renders nothing when count is 0):**
|
|
|
|
```tsx
|
|
function Badge({ count }: { count: number }) {
|
|
return (
|
|
<div>
|
|
{count > 0 ? <span className="badge">{count}</span> : null}
|
|
</div>
|
|
)
|
|
}
|
|
|
|
// When count = 0, renders: <div></div>
|
|
// When count = 5, renders: <div><span class="badge">5</span></div>
|
|
```
|