What is the difference between int and int (num) in MySQL? Solving ideas

What is the difference between int and int (num) in MySQL?
For example, what is the difference between int (num) and int? It seems that the display width is not limited in the actual data insertion, except for the addition of the Zerofill attribute, which must occupy the function of num bit.

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No difference.
As an exception, you already know that the Zerofill property is bound to Num

The tool generates a maximum width to remind you of the maximum number of digits, so you don't have to know
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This is the same as the C-style formatted string, which is displayed in full when the limit is exceeded.

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