Javascript 反应:如何更新对象的属性?
我想在Javascript 反应:如何更新对象的属性?,javascript,reactjs,mongodb,Javascript,Reactjs,Mongodb,我想在incLikes函数中将单个blog的喜欢度增加1,并将更新后的blog恢复为blogs状态 My mongo数据库包含以下博客: [ { "title": "The lost planet in the milky way", "author": "Ford Beeblebrox", "url": "www.goldenpl
incLikes
函数中将单个blog的喜欢度增加1,并将更新后的blog恢复为blogs状态
My mongo数据库包含以下博客:
[
{
"title": "The lost planet in the milky way",
"author": "Ford Beeblebrox",
"url": "www.goldenplanet.milky.way",
"likes": 102,
"id": "600aabcbf4492017c4068727"
},
{
"title": "How the Vogols destroyed the Earth",
"author": "Michael Faraday",
"url": "www.far-far-aday.com",
"likes": 45,
"id": "600ab1575883720a04743319"
}
]
为了给你一个更全面的背景,你可以这样做:
const [blogs, setBlogs] = React.useState(all_blogs);
const incLikes = (blog) => {
setBlogs(
blogs.map((b) => {
if (b.id === blog.id) b.likes++;
return b;
})
);
};
return (
<div className="App">
<h1>Blogs:</h1>
{blogs.map((item, i) => (
<div key={i}>
{item.title} (Likes: {item.likes}) --{" "}
<button onClick={() => incLikes(item)}> Like</button>
</div>
))}
</div>
);
const[blogs,setBlogs]=React.useState(所有博客);
const incLikes=(博客)=>{
挫折(
blogs.map((b)=>{
如果(b.id==blog.id)b.likes++;
返回b;
})
);
};
返回(
博客:
{blogs.map((项目,i)=>(
{item.title}(Likes:{item.Likes})--{''}
incLikes(项目)}>Like
))}
);
因此,我们的想法是将blog对象传递到函数中,然后映射到状态中存储的所有blog对象,并增加匹配的blog对象。这是给你的礼物
const [blogs, setBlogs] = React.useState(all_blogs);
const incLikes = (blog) => {
setBlogs(
blogs.map((b) => {
if (b.id === blog.id) b.likes++;
return b;
})
);
};
return (
<div className="App">
<h1>Blogs:</h1>
{blogs.map((item, i) => (
<div key={i}>
{item.title} (Likes: {item.likes}) --{" "}
<button onClick={() => incLikes(item)}> Like</button>
</div>
))}
</div>
);