How can I convert integer into float in Java?

JavaIntegerFloating Point

Java Problem Overview


I have two integers x and y. I need to calculate x/y and as outcome I would like to get float. For example as an outcome of 3/2 I would like to have 1.5. I thought that easiest (or the only) way to do it is to convert x and y into float type. Unfortunately, I cannot find an easy way to do it. Could you please help me with that?

Java Solutions


Solution 1 - Java

You just need to cast at least one of the operands to a float:

float z = (float) x / y;

or

float z = x / (float) y;

or (unnecessary)

float z = (float) x / (float) y;

Solution 2 - Java

You just need to transfer the first value to float, before it gets involved in further computations:

float z = x * 1.0 / y;

Solution 3 - Java

You shouldn't use float unless you have to. In 99% of cases, double is a better choice.

int x = 1111111111;
int y = 10000;
float f = (float) x / y;
double d = (double) x / y;
System.out.println("f= "+f);
System.out.println("d= "+d);

prints

f= 111111.12
d= 111111.1111

Following @Matt's comment.

float has very little precision (6-7 digits) and shows significant rounding error fairly easily. double has another 9 digits of accuracy. The cost of using double instead of float is notional in 99% of cases however the cost of a subtle bug due to rounding error is much higher. For this reason, many developers recommend not using floating point at all and strongly recommend BigDecimal.

However I find that double can be used in most cases provided sensible rounding is used.

In this case, int x has 32-bit precision whereas float has a 24-bit precision, even dividing by 1 could have a rounding error. double on the other hand has 53-bit of precision which is more than enough to get a reasonably accurate result.

Solution 4 - Java

// The integer I want to convert

int myInt = 100;

// Casting of integer to float

float newFloat = (float) myInt

Solution 5 - Java

Here is how you can do it :

public static void main(String[] args) {
	// TODO Auto-generated method stub
	int x = 3;
	int y = 2;
	Float fX = new Float(x);
	float res = fX.floatValue()/y;
	System.out.println("res = "+res);
}

See you !

Solution 6 - Java

Sameer:

float l = new Float(x/y)

will not work, as it will compute integer division of x and y first, then construct a float from it.

float result = (float) x / (float) y;

Is semantically the best candidate.

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Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionRomanView Question on Stackoverflow
Solution 1 - JavaMatt BallView Answer on Stackoverflow
Solution 2 - Javauser unknownView Answer on Stackoverflow
Solution 3 - JavaPeter LawreyView Answer on Stackoverflow
Solution 4 - Javatej shahView Answer on Stackoverflow
Solution 5 - JavaLaGrandMereView Answer on Stackoverflow
Solution 6 - JavaLostOblivionView Answer on Stackoverflow