CODEWITHSUNDEEP
javascriptreactjsreduxreact-redux
Sam
Sam

Reputation: 30302

Sending number instead of string from Select in React component

I have a "controlled" React component for a very simple drop down that looks like this:

const MyDropDown = ({field, handleChange}) => {

   return(

      <select name="myField" value={field} onChange={handleChange}>
         <option value="1">Apples</option>
         <option value="2">Oranges<option>
         <option value="3">Bananas</option>
      <select>
   );
}

MyDropDown.propTypes = {
   field: PropTypes.number.isRequired,
   handleChange: PropTypes.func.isRequired
}

export default MyDropDown;

Initially, I set the value of the field to 0 in my reducer. This is the right thing to do because the value will always be a number. The problem I'm having is this:

Initially, everything is fine but when I make a selection, I get a warning saying an invalid prop of type string is supplied and it was expecting a number.

How do I make sure the values in the options are numbers and not strings?

BTW, I tried not using quotes for option values but React doesn't seem to like it i.e. <option value=1>Apples</option>

Upvotes: 16

Views: 16665

Answers (2)

Igor Ljevak
Igor Ljevak

Reputation: 61

if your handler looks like above you can use +e.target.value

Upvotes: 4

teaflavored
teaflavored

Reputation: 440

I assume your handleChange looks something like this

handleChange(e) {
    this.setState({ val: e.target.value});
}

The issue here is that html needs quotes around the attribute values, so in essence e.target.value resolves to a string. A simple fix would be to parse it into a number by using

parseInt(e.target.value, 10);

Upvotes: 19

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