# hasProperty method

bool hasProperty (dynamic property)

Returns `true` if the JavaScript object contains the specified property either directly or though its prototype chain.

This is the equivalent of the `in` operator in JavaScript.

## Implementation

    bool hasProperty(property) {
      if (property is! String && property is! num) {
        throw new ArgumentError("property is not a String or num");
      }
      return JS('bool', '# in #', property, _jsObject);
    }