The code in the above site was created in the same way as the directory and executed. However, there are some syntax errors because the article is old. I fixed what I can fix, but breakpoint.jsx,
TypeError: Cannot read property'string'of undefined error in const {string, object} = React.PropTypes;What should I do about this?

  • Answer # 1

    React.PropTypesis deprecated in React 15.5 and is separated into a separate package calledprop-types.

    import PropTypes from'prop-types', let's sayconst {string, object} = PropTypes;(official explanation).