How to update the value from the updated Array?

user_6913838 0
Viewed 40

I have an array by default with all the checkbox status as true.

let initialarray = [{name: 'Approved', isChecked: true},
                    {name: 'Rejected', isChecked: true},
                    {name: 'Pending', isChecked: true},
                    {name: 'Cancelled', isChecked: true}]

All the checkboxes are selected, As I set checked to true

When I try to uncheck the approved status I can able to update the respective Object checked status to false.

My OnChange Function looks like Below

const onChange = (e) => {
 const updatedStatus = initialarray.map((item) =>
  item.name === e.target.name
    ? { ...item, isChecked: e.target.checked }
    : item
 );
};



 updatedstatus= [{name: 'Approved', isChecked: false},
                {name: 'Rejected', isChecked: true},
                {name: 'Pending', isChecked: true},
                {name: 'Cancelled', isChecked: true}]

When I try to uncheck the Rejected name, I am able to update on the rejected status object but the Approved name status again changing to true.

 updatedstatus= [{name: 'Approved', isChecked: true},
                {name: 'Rejected', isChecked: false},
                {name: 'Pending', isChecked: true},
                {name: 'Cancelled', isChecked: true}]

Latest Updated status only I can able to change. other status it was resetting to true

Expected:

expected= [{name: 'Approved', isChecked: false},
                {name: 'Rejected', isChecked: false},
                {name: 'Pending', isChecked: true},
                {name: 'Cancelled', isChecked: true}]
reactjs checkbox function arrays javascript
3 Answers

You also need to replace the initialStatus with the updated status. You are again and again looping on the initialArray and never updating it.

const onChange = (e) => {
 const updatedStatus = initialarray.map((item) =>
  item.name === e.target.name
    ? { ...item, isChecked: e.target.checked }
    : item
 );
initialarray = updatedStatus;
};
user_176684260

Store that array as a state since states will persist between component updates.

When setting the state in the onChange, use a call back that takes prevState.

const { useState } = React

function App() {
  const [checkboxes, setCheckboxes] = useState(
    [
      {name: 'Approved', isChecked: false},
      {name: 'Rejected', isChecked: true},
      {name: 'Pending', isChecked: true},
      {name: 'Cancelled', isChecked: true}
    ]
  )

  const onChange = (e) => {
    setCheckboxes(prevState =>  prevState.map((item) =>
    item.name === e.target.name
      ? { ...item, isChecked: e.target.checked }
      : item
    ))
  };
  
  console.log(checkboxes)
              
  return (
    <div>
      {checkboxes.map((box, i) => 
        <input
          type="checkbox" 
          checked={box.isChecked} 
          onChange={onChange} 
          name={box.name} 
          key={i} />
      )}
    </div>
  )
                
}

ReactDOM.render(<App />, window.root)
<script crossorigin src="https://unpkg.com/react@18/umd/react.production.min.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@18/umd/react-dom.production.min.js"></script>

<div id="root"></div>

user_178040160

The issue is that you are using initialarray to update the state.

const updatedStatus = initialarray.map(...

Instead of you need to use the prevoState object in the setState callback.

const initialarray = [
  { name: "Approved", isChecked: true },
  { name: "Rejected", isChecked: true },
  { name: "Pending", isChecked: true },
  { name: "Cancelled", isChecked: true }
];

function App() {
  const [state, setState] = React.useState(initialarray);

  const onChange = (name) => {
    setState((prevState) =>
      prevState.map((item) =>
        item.name === name ? { ...item, isChecked: !item.isChecked } : item
      )
    );
  };
  
  return (
    <div>
      {state.map(({ name, isChecked }) => (
        <React.Fragment key={name}>
          <input
            type="checkbox"
            id={name}
            checked={isChecked}
            onChange={() => onChange(name)}
          />
          <label htmlFor={name}> {name}</label>
          <br />
        </React.Fragment>
      ))}
    </div>
  );
}

ReactDOM.render(<App />, document.querySelector('.react'));
<script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<div class='react'></div>

user_85104050
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