How can I use parseInt for a double?

Question

My program receives some input (a String ). It is rather possible that the input is in the form of a double , like "1.5" . But I would like to convert it to an integer , so I can end up with just a 1 .

First, I tried this:

Integer.parseInt(someString);

But it doesn't work - I'm assuming it is because of the dot . that it can't parse it.

So I thought that maybe the Integer class can create an integer from a double . So I decided to create a double and then make it an int , like this:

Integer.parseInt(Double.parseDouble(someString));

But apparently there is

no suitable method found for parseInt(double)

So, what do you suggest? Are there one-liners for this? I thought about making a method that removes the dot and all characters after it... but that doesn't sound very cool.

Answer 1

It is safe to parse any numbers as double , then convert it to another type after. Like this:

// someString = "1.5";
double val = Double.parseDouble(someString);  // -> val = 1.5;
int intVal = (int) Math.floor(val);           // -> intVal = 1;

Note that with Java 7 (not tested with earlier JVM, but I think it should work too), this will also yield the same result as above :

int intVal = (int) Double.parseDouble(someString);

as converting from a floating value to an int will drop any decimal without rounding.

Answer 2

use casting.

double val = Double.parseDouble(someString);  
int intVal = (int) Math.floor(val);   

Answer 3

You've got the Double , I assume, with Double.parseDouble . So just use:

int i = (int) Double.parseDouble(someString);

Answer 4

尝试，

int no= new Double(string).intValue();

Answer 5

Try this:

1) Parse the string as double 2) cast from double to int

public static void main(String[] args) {
    String str = "123.32";
    int i = (int) Math.floor(Double.parseDouble(str));
    System.out.println(i);

}