java check if 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 the given string is a number

//Add this to your code and call
static private boolean isMyNumber(String s){
        try{
            Integer.parseInt(s);
            return true;
        }catch (Exception e){
            return false;
        }
    }

Example 3: 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");

Example 4: java check if int

//"% (modulo)" calulates the remainder when the value on the left is divided by the value on the right

float number = 20;

if(number%1 == 0){
	println("It is an integer");
} else {
	println("It is not an integer");
}