ReactJS:如何使用react钩子将现有数组添加到另一个数组?

问题描述 投票:0回答:2

我正在尝试使用react挂钩将数组添加到现有数组。我唯一的问题是我尝试执行的所有操作都导致无法填充数组...

const [ residenceFinal, setResidenceFinal ] = useState([]);

我在这里和下面创建值,我试图将一个现有数组添加到ResidenceFinal。

const predefinedMenuItems = {
      residences: {
            closeOnClick: false,
            setActiveOnClick: true,
            tooltip: "Residences",
            content: <i className='fas fa-city'/>,
            onClick: () => {
                dispatch(getValue(value));
            },
            getContent: (controlledEntity) => {
                const divTitle = "Residence info";

                let res = controlledEntity.info;
                const {data} = res;
                let residencesInfo = [];
                _.isArray(data) ? residencesInfo = data : residencesInfo.push(data);

                let resiFinal = residencesInfo.map(function(el) {
                    var o = Object.assign({}, el);
                    o.isActive = false;
                    return o;
                  })

                setResidenceFinal(resiFinal);
                return <div className="open-data-information-drawer-item residences">
                    <h1>{divTitle}</h1>
                    <div className="open-data-item-information-container">
                        {residenceFinal.map((residence, idx) => {
                            return <div className={"open-data-item-information-container-item "+ (residence.isActive ? 'active' : '') + " item-" + idx}  onClick={ (e) => onClickIdentification(residence, idx)} key={idx}>
                                {getOpenDataLi(residence, "identificatiecode")}
                                {getOpenDataLi(residence, "status")}
                                {getOpenDataLi(residence, "oppervlakte")}
                        }
                            </div>;
                        })}
                    </div>
                </div>;

            }
       }
}

因此,我尝试了很多变体来将resiFinal添加到ResidenceFinal(我将其固定时,命名将会更改),但是每次我检查时,residenceFinal仍然为空...

有人可以帮我吗?

编辑:在使用getContent的地方添加。

const [ drawerContent, setDrawerContent ] = useState(<div></div>);
function handleClick(index, e) {
        const selectedMenuItem = menuItems.find(m => m.id === index);

        setDrawerContent(selectedMenuItem.getContent(openData));
    }
<List.Item >
    <div key={predefinedMenuItemId} onClick={ e => handleClick(predefinedMenuItemId, e)}  className={isMenuItemActive ?  'list-item list-item-' + predefinedMenuItemId  : 'list-item list-item-' + predefinedMenuItemId }></div>
</List.Item >

arrays reactjs react-hooks
2个回答
0
投票

将数组添加到现有数组的方法

  • push()方法

  • 扩展运算符

  • concat()方法

let array = [1,2];
array.push(...[3,4])
console.log(array)

let array2 = [10,11];
let newArray = [...array2, ...[12,13]];
console.log(newArray)

let array3 = [20,21];
let newArray2 = [22,23].concat(...array3)
console.log(newArray2)

您可以使用这种方式添加。

setResidenceFinal([...residenceFinal, ...resiFinal]);

0
投票

您需要使用扩展语法

其工作方式示例:

var colors = ['red', 'green', 'blue'];
var refColors = [...colors, 'yellow'];
//colors => ['red', 'green', 'blue']
//refColors => ['red', 'green', 'blue', 'yellow']

适合您的情况

setResidenceFinal(current => [...current, ...resiFinal])
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