How to add an item to the todo list-CodePudding

This is a short cut of my addItem function in my todo app, i don't really understand what slice does in this value: this.state.newItem.slice(). Can anybody explain me? Thank you so much!

constructor(props) {
    super(props);
    this.state = {
      newItem: "",
      list: []
    };

addItem() {
    // create a new item with unique id
    const newItem = {
      id: 1   Math.random(),
  

    **value: this.state.newItem.slice()**

 
    };

    // copy current list of items
    const list = [...this.state.list];

    // add the new item to the list
    list.push(newItem);

    // update state with new list, reset the new item input
    this.setState({
      list,
      newItem: ""
    });
  }

CodePudding user response：

Since the slice returns new string, the slice might have used to copy the string in the above code. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice

CodePudding user response：

First of all why are you use slice method? If you used it to trim your value. you use The trim() method removes whitespace from both sides of a string. The trim() method does not change the original string. Syntax. string.trim().