java check string is a number code example

Example 1: java check if string is number

try {
    int n = Integer.parseInt(str);
} catch (NumberFormatException e) {
    // str is not a number
}

Example 2: check if string is decimal java

Scanner in = new Scanner(System.in);
		
		String ip1 = in.nextLine();
		
		if( ip1.matches("^\\d+\\.\\d+") ) 
			System.out.println(ip1+"----is a decimal number");
		else
			System.out.println(ip1+"----is a not decimal number");