Java verifies whether it is a number

java determines whether it is a number:

int id = 12345689797;
Pattern pattern = Pattern.compile("[0-9]*");
Matcher isNum = pattern.matcher(id);
if( !isNum.matches() ){
  //不是数字
}else{
  //是数字
}

matches() method is used to detect whether a string matches a given regular expression.

Syntax

public boolean matches(String regex)

Parameters

regex -- Regular expression that matches strings.

Return value

Returns true when the string matches the given regular expression.

For more java knowledge, please pay attention to java basic tutorial.

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