Javascript 嵌套时未呈现的有效组件
我在渲染组件组合时遇到此错误。我找不到错误在哪里。我做错了什么?如何通过从控制台读取来读取错误的确切位置Javascript 嵌套时未呈现的有效组件,javascript,reactjs,Javascript,Reactjs,我在渲染组件组合时遇到此错误。我找不到错误在哪里。我做错了什么?如何通过从控制台读取来读取错误的确切位置 var Hamburger = React.createClass({ render: function(){ return( <img id="hamburger" src="hamburger.png"/> ) } }); var Search = React.createClass({ ren
var Hamburger = React.createClass({
render: function(){
return(
<img id="hamburger" src="hamburger.png"/>
)
}
});
var Search = React.createClass({
render: function(){
return(
<div>
<input id ="search-input" type="text" placeholder = "Search your favorites"/>
<img id="search-img" src = "search.png"/>
</div>
)
}
});
var Cart = React.createClass({
render: function(){
return(
<img id ="cart" src = "cart.png"/>
)
}
});
var Header = React.createClass({
render: function(){
return(
<div id="header">
<Hamburger/>
<Search/>
<Cart/>
</div>
)
}
});
// Scroll bar for categories
var Tab = React.createClass({
render: function(){
return(
<p>{this.props.name}</p>
)
}
})
var tabNames = ["VEG PIZZA","NON-EG PIZZA","PIZZA MANIA","BURGER PIZZA","SIDES AND BEVERAGES"];
var ScrollBar = React.createClass({
render: function(){
var tabs = [];
for (var i = 0; i < tabNames.length; i++) {
tabs.push(
<Tab name = {tabNames[i]} key={i}/>
)
}
return(
<div id = "scrollbar">{tabs}</div>
)
}
});
var Quickadd = React.createClass({
render: function(){
return(
<input className = "action-btn" type="button" value="Quick Add"/>
)
}
});
var Item = React.createClass({
render: function(){
return(
<div className= "item-tab">
<img className="pizza-img" src={this.props.source}/>
<div className="item-title">{this.props.title}</div>
<div className="item-desc">{this.props.desc}</div>
<div className="item-price">{this.props.price}</div>
<div className="size-btns">
<input className="size-btn" type="button" value="Regular"/>
<input className="size-btn" type="button" value="Medium"/>
<input className="size-btn" type="button" value="Large"/>
</div>
<div className = "action-btns">
<input className = "action-btn" type="button" value="Quick Add"/>
<Quickadd/>
</div>
</div>
)
}
});
var Pizzas = [
{
title: "Pizza1",
description: "Lorem ipsum dolor sit amet, insolens expetenda euripidis sit ne, nec et option aperiri, id vel verear verterem imperdiet.",
price: "₹910",
image: "images/pizza.jpg"
},
{
title: "Pizza2",
description: "Lorem ipsum dolor sit amet, insolens expetenda euripidis sit ne, nec et option aperiri, id vel verear verterem imperdiet.",
price: "₹545",
image: "images/pizza.jpg"
},
{
title: "Pizza3",
description: "Lorem ipsum dolor sit amet, insolens expetenda euripidis sit ne, nec et option aperiri, id vel verear verterem imperdiet.",
price: "₹654",
image: "images/pizza.jpg"
},
{
title: "Pizza4",
description: "Lorem ipsum dolor sit amet, insolens expetenda euripidis sit ne, nec et option aperiri, id vel verear verterem imperdiet.",
price: "₹785",
image: "images/pizza.jpg"
},
{
title: "Pizza5",
description: "Lorem ipsum dolor sit amet, insolens expetenda euripidis sit ne, nec et option aperiri, id vel verear verterem imperdiet.",
price: "₹687",
image: "images/pizza.jpg"
}
];
var ItemContainer = React.createClass({
render: function(){
var items = [];
for (var i = 0; i < items.length; i++) {
items.push(<Item source={Pizzas[i].image} title={Pizzas[i].title} desc={Pizzas[i].description} price={Pizzas[i].price} key={i}/>)
}
return(
<div className="items">
{items}
</div>
)
}
});
var MainContent = React.createClass({
render: function(){
<div className="main-content">
<Header/>
<ScrollBar/>
<ItemContainer/>
</div>
}
});
ReactDOM.render(<MainContent/>,document.getElementById('workspace'));
var Hamburger=React.createClass({
render:function(){
返回(
)
}
});
var Search=React.createClass({
render:function(){
返回(
)
}
});
var Cart=React.createClass({
render:function(){
返回(
)
}
});
var Header=React.createClass({
render:function(){
返回(
)
}
});
//类别滚动条
var Tab=React.createClass({
render:function(){
返回(
{this.props.name}
)
}
})
var tabNames=[“蔬菜披萨”、“非EG披萨”、“披萨狂热”、“汉堡披萨”、“配菜和饮料”];
var ScrollBar=React.createClass({
render:function(){
var标签=[];
对于(var i=0;i
我在ReactDOM.render中将MainContent替换为Header、ScrollBar和ItemContainer,它们将分别被渲染。但MainContent未呈现,这是错误:
未捕获不变冲突:MainContent.render():有效的React
元素(或null)必须返回。您可能返回了未定义的,
数组或其他无效对象
请解释发生的原因?您没有从
MainContent
render
函数返回,这意味着您的MainContent
正在返回未定义的:
var MainContent = React.createClass({
render: function(){
return (
<div className="main-content">
<Header/>
<ScrollBar/>
<ItemContainer/>
</div>
)
}
});
var MainContent=React.createClass({
render:function(){
返回(
)
}
});
您没有从MainContent
render
功能返回,这意味着您的MainContent
正在返回未定义的:
var MainContent = React.createClass({
render: function(){
return (
<div className="main-content">
<Header/>
<ScrollBar/>
<ItemContainer/>
</div>
)
}
});
var MainContent=React.createClass({
render:function(){
返回(
)
}
});
您需要从MainContent
返回有效的React元素。请执行以下操作
var MainContent = React.createClass({
render: function(){
return <div className="main-content">
<Header/>
<ScrollBar/>
<ItemContainer/>
</div>
}
});
var MainContent=React.createClass({
render:function(){
返回
}
});
您需要从MainContent
返回有效的React元素。请执行以下操作
var MainContent = React.createClass({
render: function(){
return <div className="main-content">
<Header/>
<ScrollBar/>
<ItemContainer/>
</div>
}
});
var MainContent=React.createClass({
render:function(){
返回
}
});
React中的返回语句如果跨越多行,则必须用括号括起来。这将引发错误。您返回的是单个节点。它不需要括号。它不会抛出错误。你自己试试吧!React中的返回语句如果跨越多行,则必须用括号括起来。这将引发错误。您返回的是单个节点。它不需要括号。它不会抛出错误。你自己试试吧!