Page History

...

Instead of returning props.label, you accidentally misspelled it is as 'props.lable'. When loaded into the browser, there would be no error detected. Only when the class was loaded using ReactDOM.render() would the error be detected and that would only be a problem determined by the lack of the label. There is no real error except one of omission. A small typo could lead to a long debugging session.

...

If you are only using a simple text editor and the command line to compile your code, the compile will detect the mistake before you can run the code.

...