Accepted answer

React.PropTypes.arrayOf( React.PropTypes.number ) just returns a function, so you can instead provide your own function to perform the validation.

Your function will be passed three parameters: props, propName, componentName

see the second to last example shown in React.PropTypes from the docs.

So a function that should satisfy your constraints would be:

function isTwoElementArrayOfNumbers( props, propName, componentName ){
  var _array = props[ propName ];

  if( _array && _array.constructor === Array && _array.length === 2 ){

    if( !_array.every(
      function isNumber( element ){
        return typeof element === 'number';

      return new Error('elements must be numbers!');
    return new Error('2 element array of numbers not provided!');
} your react element
  numArray: isTwoElementArrayOfNumbers


I don't know about extending them, I'm not sure that's possible.

But you could store the above as an exported constant and use it to compose properties of other propTypes (but I think you probably already know this):

export const CustomProp = Array.PropType.arrayOf(Array.PropType.number)

export const OtherCustomProp = contains({
 foo: React.PropTypes.string,
 bars: CustomProp

Related Query

More Query from same tag