webpack ReactJS：位于this.setState的意外令牌

Question

I am trying to change state of all the elements in an array in ReactJS as shown below. This is my First application, so I am not able to know what is wrong in over here.

closeState(){
    this.state.itemList.forEach(function(itemInd){
        this.setState({ itemInd.expState : 0 });
    }
});

It gives me Unexpected token error

I have

     this.state = {
         ...........
        itemList: [],
         .....
     }

each element in itemList has : title, desc, expState .

Answer 1

I think you chose wrong way to solve this issue., from your example I understood that you want to set expState to 0 , for each element in itemList ., if it is true better do it like this

const newItemListState = this.state.itemList.map((itemInd) => {
  return Object.assign(itemInd, { expState: 0 });
});

this.setState({ itemList: newItemListState })

---

In your example you have several mistakes

1. You forgot add ) after callback function

2. You need set this for .forEach callback, or use arrow function

   2.1. this.state.itemList.forEach(function(itemInd) { }, this);

   2.2. this.state.itemList.forEach((itemInd) => { });

3. You can't use this { itemInd.expState : 0 } expression.