props: {

    title: String,

    default: function () {

      return "John Doe";

    },

  },

props: {

  name: {

    type: String,

    default: 'John Doe'

  }

}

defineProps({

  // Basic type check

  //  (`null` and `undefined` values will allow any type)

  propA: Number,

  // Multiple possible types

  propB: [String, Number],

  // Required string

  propC: {

    type: String,

    required: true

  },

  // Required but nullable string

  propD: {

    type: [String, null],

    required: true

  },

  // Number with a default value

  propE: {

    type: Number,

    default: 100

  },

  // Object with a default value

  propF: {

    type: Object,

    // Object or array defaults must be returned from

    // a factory function. The function receives the raw

    // props received by the component as the argument.

    default(rawProps) {

      return { message: 'hello' }

    }

  },

  // Custom validator function

  // full props passed as 2nd argument in 3.4+

  propG: {

    validator(value, props) {

      // The value must match one of these strings

      return ['success', 'warning', 'danger'].includes(value)

    }

  },

  // Function with a default value

  propH: {

    type: Function,

    // Unlike object or array default, this is not a factory

    // function - this is a function to serve as a default value

    default() {

      return 'Default function'

    }

  }

})