Remove item from array in React

Question

I have problem with removeItem function (it should remove current

that button is nested in, and item from array on this.state.list), no code currentl

Answer 1

import React, { Component } from 'react';
import './Todo.css';

class Todo extends Component {
  constructor(props) {
    super(props);
    this.state = {
      list: [],
      text: ''
    }
    this.textChange = this.textChange.bind(this);
    this.addToList = this.addToList.bind(this);
  }

  textChange(e) {
    this.setState({
      text: e.target.value
    })
  }

  addToList() {
    this.setState(prevState => ({
      list: prevState.list.concat(this.state.text),
      text: ''
    }))
  }

  removeItem(index) {
    let newList = this.state.list.splice(index,1);
    this.setState({list:newList})
  }

  render() {
    return(
      <div>
        <h1>My Todo List</h1>
        <h3>Add item</h3>
        <input value={this.state.text} onChange={e => this.textChange(e)}/>
        <button onClick={this.addToList}>+</button>
        <ul>{this.state.list.map((x,y) => {
          return <li key={y}>{x}
          <button onClick={this.removeItem.bind(this,y)}>-</button>
          </li>})}
        </ul>
      </div>
    )
  }
}

export default Todo;

Answer 2

I think you should pass the index of the item to your removeItem function. Like so:

removeItem(index) {
  const list = this.state.list;

  list.splice(index, 1);
  this.setState({ list });
}

render() {
  return(
    <div>
      <h1>My Todo List</h1>
      <h3>Add item</h3>
      <input value={this.state.text} onChange={e => this.textChange(e)}/>
      <button onClick={this.addToList}>+</button>
      <ul>{
        this.state.list.map((text, i) => {
          return (
            <li key={i}>
              {text}
              <button onClick={() => this.removeItem(i) }>-</button>
            </li>
          );
        })}
      </ul>
    </div>
  )
}

Answer 3

You can filter your list by the issue you want, and it will be auto removed, for example, if you want to remove all items = 3 :

list: prevState.list.filter(x=> x != 3);

Good luck!

Answer 4

Removing item from array by index:

const newList = this.state.list.splice(index, 1);

Removing item from array by value:

const newList = this.state.list.splice(this.state.list.indexOf(value), 1);

Answer 5

in my solution eg:

const remove = (i) => {
        const arr = data.filter((item) => item.name !== i);
        setData(arr);
    };

I filtered the items that are not removed and set again the state

Answer 6

I would pass the index of the item in the list on click then splice the array:

<ul>
  {
    this.state.list.map((x,y) => {
      return (
        <li key={y}>
          {x}
          <button onClick={() => this.removeItem(y)}>-</button>
        </li>
      );
    })
  }
</ul>

Then in removeItem:

removeItem(index) {
  const list = this.state.list;
  list.splice(index, 1);
  this.setState({ list });
}