简体   繁体   中英

Update array object object value using spread operator

I am trying to update a value from an array object and object. my sample code is below. Not getting the result as I expected. It would be nice if someone can help?

    let array = [
        {   
            id:"01",
            "name": {
                "value": "jaison",
                "error": null
            },
            "email": {
                "value": "jaison@yopmail.com",
                "error": null
            }
        },
        {
            id:"02",
            "name": {
                "value": "jaison 1",
                "error": null
            },
            "email": {
                "value": "jaison1@yopmail.com",
                "error": null
            }
        }
    ];

    this.state{
        data:array
    }

    //This two data getting a from a form
    const key = "02";
    const editedData = {name:"updated jaison 1", email:"updatedjaison1@yopmail.com"}

    const newData = [...this.state.data];

    const index = newData.findIndex(item => key === item.id);

    let item = newData[index];

    //Working as expcted 
    console.log('1', item);

    Object.keys(editedData).forEach(function (key) {
      item[key] = editedData[key];
    });

    //Working as expcted 
    console.log('2', item);

    this.setState({ data: [...this.state.data, item]}, () => {
        //Not Working as expcted 
        console.log(this.state.data);
    });

    Expected result
   let array = [
    {   
        id:"01",
        "name": {
            "value": "jaison",
            "error": null
        },
        "email": {
            "value": "jaison@yopmail.com",
            "error": null
        }
    },
    {
        id:"02",
        "name": {
            "value": "updated jaison 1",
            "error": null
        },
        "email": {
            "value": "updatedjaison1@yopmail.com",
            "error": null
        }
    }
];

When you update item[key] inside the forEach , it just updates name and email with a string values. Also, it mutates the state

Instead, you could loop throguh editedData object update the clone of that specific index. Use the spread syntax to keep error and other properties as it is and update only the value property. Then update the index of the cloned data array and call setState like this:

const key = "02",
      editedData = { name: "updated jaison 2", email: "updatedjaison2@yopmail.com" },
      data = [...this.state.data],
      index = data.findIndex(item => key === item.id),
      updatedData = { ...data[index] };

// loop through and update only the keys you need 
for(const key in editedData) {
  updatedData[key] = { ...updatedData[key], value: editedData[key] }
}

data[index] = updatedData;

this.setState({ data })

Instead of finding the index and using a forEach to loop over the array, I'd do something like:

const updatedArray = newData.map(item => {
   // if editedData has a key attribute:
   if (item.id === editedData.key) {
       return editedData; //you'd need to add a key attribute to the data
   } else {
       return item;
   }
});
this.setState({data: updatedArray});

You can just use map :

   let array = [
        {   
            id:"01",
            "name": {
                "value": "jaison",
                "error": null
            },
            "email": {
                "value": "jaison@yopmail.com",
                "error": null
            }
        },
        {
            id:"02",
            "name": {
                "value": "jaison 1",
                "error": null
            },
            "email": {
                "value": "jaison1@yopmail.com",
                "error": null
            }
        }
    ];

    const key = "02";

    const updated = array.map(item => {
        if (item.id === key) {
            return {id: key, name:"updated jaison 1", email:"updatedjaison1@yopmail.com"}
        }
        return item;
    });

setState({data: updated});

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM