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Merge pull request #967 from reactjs/sync-7d50c3ff
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Sync with react.dev @ 7d50c3f
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titovmx committed Aug 27, 2024
2 parents a953d8a + b143938 commit 992b062
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Showing 5 changed files with 26 additions and 21 deletions.
4 changes: 2 additions & 2 deletions src/content/blog/2023/03/16/introducing-react-dev.md
Original file line number Diff line number Diff line change
Expand Up @@ -269,7 +269,7 @@ Use the conditional operator (`cond ? a : b`) to render a ❌ if `isPacked` isn
function Item({ name, isPacked }) {
return (
<li className="item">
{name} {isPacked && ''}
{name} {isPacked && ''}
</li>
);
}
Expand Down Expand Up @@ -307,7 +307,7 @@ export default function PackingList() {
function Item({ name, isPacked }) {
return (
<li className="item">
{name} {isPacked ? '' : ''}
{name} {isPacked ? '' : ''}
</li>
);
}
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32 changes: 16 additions & 16 deletions src/content/learn/conditional-rendering.md
Original file line number Diff line number Diff line change
Expand Up @@ -52,13 +52,13 @@ export default function PackingList() {
</Sandpack>

Обратите внимание, что у некоторых компонентов `Item` проп `isPacked` имеет значение `true`, вместо значения `false`. Если `isPacked={true}`, вы хотите добавить галочку() к упакованным вещам.
Обратите внимание, что у некоторых компонентов `Item` проп `isPacked` имеет значение `true`, вместо значения `false`. Если `isPacked={true}`, вы хотите добавить галочку() к упакованным вещам.

Можно реализовать это с помощью [управляющей конструкции `if`/`else`](https://developer.mozilla.org/ru/docs/Web/JavaScript/Reference/Statements/if...) таким образом:

```js
if (isPacked) {
return <li className="item">{name} </li>;
return <li className="item">{name} </li>;
}
return <li className="item">{name}</li>;
```
Expand All @@ -70,7 +70,7 @@ return <li className="item">{name}</li>;
```js
function Item({ name, isPacked }) {
if (isPacked) {
return <li className="item">{name} </li>;
return <li className="item">{name} </li>;
}
return <li className="item">{name}</li>;
}
Expand Down Expand Up @@ -159,7 +159,7 @@ export default function PackingList() {
В предыдущем примере вы контролировали, какое JSX дерево будет возвращено компонентом (если вообще будет!). Возможно, вы уже заметили некоторое дублирование в выводе рендера:

```js
<li className="item">{name} </li>
<li className="item">{name} </li>
```

очень похоже на
Expand All @@ -172,7 +172,7 @@ export default function PackingList() {

```js
if (isPacked) {
return <li className="item">{name} </li>;
return <li className="item">{name} </li>;
}
return <li className="item">{name}</li>;
```
Expand All @@ -187,7 +187,7 @@ return <li className="item">{name}</li>;

```js
if (isPacked) {
return <li className="item">{name} </li>;
return <li className="item">{name} </li>;
}
return <li className="item">{name}</li>;
```
Expand All @@ -197,12 +197,12 @@ return <li className="item">{name}</li>;
```js
return (
<li className="item">
{isPacked ? name + ' ' : name}
{isPacked ? name + ' ' : name}
</li>
);
```

Вы можете читать это как *"если `isPacked` равно true, тогда (`?`) рендерим `name + ' '`, в противном случае (`:`) рендерим `name`"*.
Вы можете читать это как *"если `isPacked` равно true, тогда (`?`) рендерим `name + ' '`, в противном случае (`:`) рендерим `name`"*.

<DeepDive>

Expand All @@ -222,7 +222,7 @@ function Item({ name, isPacked }) {
<li className="item">
{isPacked ? (
<del>
{name + ' '}
{name + ' '}
</del>
) : (
name
Expand Down Expand Up @@ -265,7 +265,7 @@ export default function PackingList() {
```js
return (
<li className="item">
{name} {isPacked && ''}
{name} {isPacked && ''}
</li>
);
```
Expand All @@ -280,7 +280,7 @@ return (
function Item({ name, isPacked }) {
return (
<li className="item">
{name} {isPacked && ''}
{name} {isPacked && ''}
</li>
);
}
Expand Down Expand Up @@ -337,7 +337,7 @@ let itemContent = name;

```js
if (isPacked) {
itemContent = name + ' ';
itemContent = name + ' ';
}
```

Expand All @@ -357,7 +357,7 @@ if (isPacked) {
function Item({ name, isPacked }) {
let itemContent = name;
if (isPacked) {
itemContent = name + ' ';
itemContent = name + ' ';
}
return (
<li className="item">
Expand Down Expand Up @@ -401,7 +401,7 @@ function Item({ name, isPacked }) {
if (isPacked) {
itemContent = (
<del>
{name + " "}
{name + " "}
</del>
);
}
Expand Down Expand Up @@ -464,7 +464,7 @@ export default function PackingList() {
function Item({ name, isPacked }) {
return (
<li className="item">
{name} {isPacked && ''}
{name} {isPacked && ''}
</li>
);
}
Expand Down Expand Up @@ -502,7 +502,7 @@ export default function PackingList() {
function Item({ name, isPacked }) {
return (
<li className="item">
{name} {isPacked ? '' : ''}
{name} {isPacked ? '' : ''}
</li>
);
}
Expand Down
2 changes: 1 addition & 1 deletion src/content/learn/describing-the-ui.md
Original file line number Diff line number Diff line change
Expand Up @@ -327,7 +327,7 @@ In this example, the JavaScript `&&` operator is used to conditionally render a
function Item({ name, isPacked }) {
return (
<li className="item">
{name} {isPacked && ''}
{name} {isPacked && ''}
</li>
);
}
Expand Down
4 changes: 2 additions & 2 deletions src/content/learn/you-might-not-need-an-effect.md
Original file line number Diff line number Diff line change
Expand Up @@ -408,9 +408,9 @@ function Game() {
There are two problems with this code.
One problem is that it is very inefficient: the component (and its children) have to re-render between each `set` call in the chain. In the example above, in the worst case (`setCard` → render → `setGoldCardCount` → render → `setRound` → render → `setIsGameOver` → render) there are three unnecessary re-renders of the tree below.
First problem is that it is very inefficient: the component (and its children) have to re-render between each `set` call in the chain. In the example above, in the worst case (`setCard` → render → `setGoldCardCount` → render → `setRound` → render → `setIsGameOver` → render) there are three unnecessary re-renders of the tree below.
Even if it weren't slow, as your code evolves, you will run into cases where the "chain" you wrote doesn't fit the new requirements. Imagine you are adding a way to step through the history of the game moves. You'd do it by updating each state variable to a value from the past. However, setting the `card` state to a value from the past would trigger the Effect chain again and change the data you're showing. Such code is often rigid and fragile.
The second problem is that even if it weren't slow, as your code evolves, you will run into cases where the "chain" you wrote doesn't fit the new requirements. Imagine you are adding a way to step through the history of the game moves. You'd do it by updating each state variable to a value from the past. However, setting the `card` state to a value from the past would trigger the Effect chain again and change the data you're showing. Such code is often rigid and fragile.
In this case, it's better to calculate what you can during rendering, and adjust the state in the event handler:
Expand Down
5 changes: 5 additions & 0 deletions vercel.json
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,11 @@
"destination": "/learn/rendering-lists#keeping-list-items-in-order-with-key",
"permanent": false
},
{
"source": "/docs/lists-and-keys",
"destination": "/learn/rendering-lists#keeping-list-items-in-order-with-key",
"permanent": false
},
{
"source": "/link/invalid-hook-call",
"destination": "/warnings/invalid-hook-call-warning",
Expand Down

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