在本机反应中循环数组答案

【问题标题】：Looping over array in react native在本机反应中循环数组
【发布时间】：2020-09-16 17:11:24
【问题描述】：

enter image description here这些是我的输入数组（service_item_list） ...

for (var k = 0; k < service_item_list.length; k++) {
            for (var l = 0; l < service_item_list[k].length; l++) {
                service_item_list[k][l].service_id=this.state.selected_services[k].id
            }
        }



service_item_list=[[{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''}],[{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''}]]

this.state.selected_services=[{id:'5',event_id:'1'},{id:'6',event_id:'1'}]

... 我不断得到输出： ...

service_item_list=[[{event_id:'1',service_id:'6',product_id:''},{event_id:'1',service_id:'6',product_id:''},{event_id:'1',service_id:'6',product_id:''}],[{event_id:'1',service_id:'6',product_id:''},{event_id:'1',service_id:'6',product_id:''},{event_id:'1',service_id:'6',product_id:''}]]

... 但我需要输出： ...

 service_item_list=[[{event_id:'1',service_id:'5',product_id:''},{event_id:'1',service_id:'5',product_id:''},{event_id:'1',service_id:'5',product_id:''}],[{event_id:'1',service_id:'6',product_id:''},{event_id:'1',service_id:'6',product_id:''},{event_id:'1',service_id:'6',product_id:''}]]

... 我找不到错误在哪里？？？

【问题讨论】：

标签： arrays react-native for-loop multidimensional-array iteration

【解决方案1】：

您可以使用 JavaScript 数组映射方法使事情变得更简单。所以方法是这样的：

const service_item_list=[[{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''}],[{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''},{event_id:'',service_id:'',product_id:''}]]

const selected_services=[{id:'5',event_id:'1'},{id:'6',event_id:'1'}]

const res = service_item_list.map((arr, outerIdx) => {
    return arr.map((obj) => {
        obj.service_id = selected_services[outerIdx].id
        return obj;
    })
})

console.log(res)

[
    [
        { event_id: '', service_id: '5', product_id: '' },
        { event_id: '', service_id: '5', product_id: '' },
        { event_id: '', service_id: '5', product_id: '' },
    ],
    [
        { event_id: '', service_id: '6', product_id: '' },
        { event_id: '', service_id: '6', product_id: '' },
        { event_id: '', service_id: '6', product_id: '' },
    ],
];

存储在 res 常量中的值将是您的结果，如上所示。更多关于JS数组映射方法here

【讨论】：