Trying to setState using eval() function (React Native)

Question

I'm trying to set multiple states in a for loop to be false or true depending on whether they meet the (if statement) requirement. The for loop will loop through an array of strings, each string represents a state. But I can't seem to use eval within this.setState function...

I have tried researching online but none of the solutions match my problem or what I'm trying to solve. I even tried eval(this.state.anything) = false but it still doesn't work and shows a left hand assign invalid error.

let businessState = [
      "this.state.groupName",
      "this.state.groupOwnerName",
      "this.state.groupDesc",
      "this.props.profile._id",
      "this.state.businessName",
      "this.state.businessDesc",
      "this.state.businessRegNo",
      "this.state.businessType",
      "this.state.businessEmail",
      "this.state.businessTel",
      "this.state.businessWeChat",
      "this.state.businessRegPhotoUri",
      "this.state.businessSignPhotoUri"
    ];

var temp = ""
for (i = 0; i < businessState.length; i++) {
  if (eval(businessState[i]) == ""){
    temp = businessState[i]+ "Error"

    this.setState({
      eval(temp): true
    })
  }
}

As you can see from the code above, I want to evaluate the state, and if the value that this particular state holds is an empty string "", I want to set this state name + "Error" (For example, if this.state.email is empty string "" I want to set this.state.emailError to true.

Answer 1

Instead of this.setState({eval(temp): true}) try this.setState({[temp]: true}). The brackets will output the string value stored in temp as a variable name in setState.

This article gives a good explanation

This Stack Overflow question and the accepted answer also should help