Why is 10..toString() normal but 10.toString() error when using javascript_javascript skills

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The description of the problem is like this:

Copy the code The code is as follows:

console.log(10..toString());//10
console.log(10.toString());//SyntaxError: Unexpected token ILLEGAL

Why does the former work normally but the latter reports an error?

The reason is that in JavaScript, the meaning of the "." operator after the number is uncertain. Because it may be a symbol of a floating point number, or it may be an operator that takes the properties of an object. But the JavaScript interpreter treats it as a symbol of floating point numbers, so the above code is equivalent to the following

Copy code The code is as follows:

console.log((10.).toString());//Normal
console.log((10.)toString());//In this case , of course an error was reported (End) ^_^