Java: how to output double-type number to integer format if its decimal is 0

问题

I have an array of double-type numbers {1.0, 2.3, 3.45, 7.8, 9.0, 5.0}. When outputting the numbers, I want to have those with decimal of 0 to show up like an integer: for example, 1.0 => 1, 9.0 => 9.

In java, how do you do this easily? thanks

回答1:

Not using any libraries I'd suggest:

public static String parse(double num) {
    if((int) num == num) return Integer.toString((int) num); //for you, StackOverflowException
    return String.valueOf(num); //and for you, Christian Kuetbach
}

Casting a double to int will cut off decimal places.

Feel free to convert the number to a string in whatever way you please ;)

来源：https://stackoverflow.com/questions/18834552/java-how-to-output-double-type-number-to-integer-format-if-its-decimal-is-0