React JS添加计数JSON元素

问题描述

大家！ 我使用React，我希望这样从JSON输出计数“员工”：enter image description here

[
{
    "id": 1,"departmentName": "Development","employees": [
        {
            "id": 1,"name": "Max","departmentId": 1,"salary": 20000.0,"city": "berlin","street": "First st.","bankName": "bank","cardNumber": "de12345678912"
        },{
            "id": 2,"name": "Sam","city": "new york","street": "Second st.","bankName": null,"cardNumber": null
        }
    ]
},

为了呈现JSON，我使用了DataTable

<DataTable value={this.state.departments} paginator={true} rows="25" selectionMode="single"
                           selection={this.state.selectedDepartment}
                           onSelectionChange={e => this.setState({selectedDepartment: e.value})}>
                    <Column field="id" header="ID"/>
                    <Column field="departmentName" header="Department"/>
                </DataTable>

如何为计数雇员添加字段？

解决方法

如果您使用的是this datatable（即使它没有Column字段属性），也可以为其提供选择器属性：

<Column
  selector={(row) => row.employees.length}
  name="Employees"
/>

,

实际上，这很容易

<Column field="employees.length" header="Employees"/>