Javascript 如何将相同的产品添加到带计数器的购物车?
我希望在向篮子中添加产品时不要重复。但这会被写进篮子里已经有两种或更多的这种商品。 如何在代码中实现这一点? 我知道我需要一个柜台来处理添加的产品,但我不知道怎么做。 请给我一个小费,我会很高兴得到任何帮助Javascript 如何将相同的产品添加到带计数器的购物车?,javascript,reactjs,Javascript,Reactjs,我希望在向篮子中添加产品时不要重复。但这会被写进篮子里已经有两种或更多的这种商品。 如何在代码中实现这一点? 我知道我需要一个柜台来处理添加的产品,但我不知道怎么做。 请给我一个小费,我会很高兴得到任何帮助 import React from "react"; import ReactDOM from "react-dom"; class Shop extends React.Component { constructor(props) { super(props); th
import React from "react";
import ReactDOM from "react-dom";
class Shop extends React.Component {
constructor(props) {
super(props);
this.state = {
data: [
{
id: 1,
name: "Product 1",
price: "50",
q:0
},
{
id: 2,
name: "Product 2",
price: "70",
q:0
},
{
id: 3,
name: "Product 3",
price: "80",
q:0
},
{
id: 4,
name: "Product 4",
price: "90",
q:0
},
{
id: 5,
name: "Product 5",
price: "100",
q:0
}
],
count: []
};
}
incrementCount = (item) => {
const {id, name, price, q} = item;
let array = [...this.state.count];
let indexOfStevie = array.findIndex(i => i.id === id);
array[indexOfStevie] = {...item, q: q+1}
console.log(array[indexOfStevie])
if (!array.some(i => i.id === id)) {
this.setState({
count: [...this.state.count, { id, name, price, q: q+1}]
});
}
};
delete = id => {
let array = [...this.state.count].filter(item => item.id !== id);
this.setState({
count: [...array]
});
};
render() {
return (
<div className="wrap">
<div>
<h3>products</h3>
<ul>
{this.state.data.map(item => (
<li key={item.id}>
{item.name}
{item.price}
<button
onClick={() =>
this.incrementCount(item)
}
>
add
</button>
</li>
))}
</ul>
</div>
<div>
<h3>bascket</h3>
<ul>
{this.state.count.map(item => (
<li>
{item.id}
{item.name}
<button onClick={() => this.delete(item.id)}>X</button>
</li>
))}
</ul>
<div>
{this.state.count.length == 0
? "empty"
: "total" +
this.state.count.reduce(
(accumulator, currentValue) =>
accumulator + +currentValue.price,
0
)}
</div>
</div>
</div>
);
}
}
ReactDOM.render(<Shop />, document.getElementById("todos-example"));
从“React”导入React;
从“react dom”导入react dom;
类。组件{
建造师(道具){
超级(道具);
此.state={
数据:[
{
id:1,
名称:“产品1”,
价格:“50”,
q:0
},
{
id:2,
名称:“产品2”,
价格:“70”,
q:0
},
{
id:3,
名称:“产品3”,
价格:“80”,
q:0
},
{
id:4,
名称:“产品4”,
价格:“90”,
q:0
},
{
id:5,
名称:“产品5”,
价格:“100”,
q:0
}
],
计数:[]
};
}
递增计数=(项目)=>{
const{id,name,price,q}=item;
让数组=[…this.state.count];
让indexOfStevie=array.findIndex(i=>i.id==id);
数组[indexOfStevie]={…项,q:q+1}
log(数组[indexOfStevie])
if(!array.some(i=>i.id==id)){
这是我的国家({
count:[…this.state.count,{id,name,price,q:q+1}]
});
}
};
删除=id=>{
让数组=[…this.state.count].filter(item=>item.id!==id);
这是我的国家({
计数:[……数组]
});
};
render(){
返回(
产品
{this.state.data.map(项=>(
-
{item.name}
{item.price}
此。递增计数(项)
}
>
添加
))}
巴斯克
{this.state.count.map(项=>(
-
{item.id}
{item.name}
this.delete(item.id)}>X
))}
{this.state.count.length==0
“空的”
:“总计”+
this.state.count.reduce(
(累加器,当前值)=>
累加器++当前值.price,
0
)}
);
}
}
render(,document.getElementById(“todos示例”);
这将为您的购物车留下一个表示形式{1:n,2:n,…..},其中n是数量如果在计数中找不到产品对象的id,则只添加一次产品对象。这就是为什么q没有改变;它总是1,因为当它被添加时,这就是q。如果在count中找到它,则需要增加它。尽可能保留其他代码的完整性:
incrementCount = (item) => {
const {id, name, price, q} = item;
let array = [...this.state.count];
let indexOfStevie = array.findIndex(i => i.id === id);
// if the product is currently in the count, modify it
if(indexOfStevie > -1) {
array[indexOfStevie].q++
this.setState( {
count: array
} );
} else {
// the product is not currently in count, add it
this.setState({
count: [...this.state.count, { id, name, price, q: q+1}]
});
}
};
然后,要生成总数,您需要添加数量*价格的乘积,而不仅仅是添加价格。在render()中:
incrementCount = (item) => {
const {id, name, price, q} = item;
let array = [...this.state.count];
let indexOfStevie = array.findIndex(i => i.id === id);
// if the product is currently in the count, modify it
if(indexOfStevie > -1) {
array[indexOfStevie].q++
this.setState( {
count: array
} );
} else {
// the product is not currently in count, add it
this.setState({
count: [...this.state.count, { id, name, price, q: q+1}]
});
}
};
{this.state.count.length == 0
? "empty"
: "total" +
this.state.count.reduce(
(accumulator, currentValue) =>
// add the product of quantity and price to total
accumulator + (currentValue.q * currentValue.price),
0
)}