How java checks that strings contain only numbers

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How to check that a string contains only numbers

There is a silly solution, which is to use Long.parseLong (string) to forcibly convert a string. If the string is not transformed into a shape, it must not just contain numbers, right?

But this method is too undesirable, so another ingenious way is to use regular expressions.

Public class CheckIfStringContainsDigitsOnly {public static void main (String [] args) {digitsOnlyString ("123Silence King"); digitsOnlyString ("123");} private static void digitsOnlyString (String string) {if (string.matches ("\\ d + ")) {System.out.println (" string containing only numbers: "+ string);}

The output is as follows:

Contains only numbers: 123is all the content of the article "how to check that java contains only numbers in a string". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!