How To Convert Float To Int In Java

In Java, a float data type can be converted to an int data type by using the `(int)` typecast operator. This operator forces the float value to be rounded down to the nearest integer. For example, the code `int myInt = (int) myFloat;` converts the float value stored in the variable `myFloat` to an integer stored in the variable `myInt`.

It’s important to note that any decimal component of the float will be truncated, not rounded, during the conversion process. Additionally, if the float value is too large to be stored as an int, it will result in an overflow and an incorrect result.

To avoid this, it’s recommended to use a rounding function or use the `Math.round()` method instead.

Different Approaches: How to convert float to int in java

There are several different approaches to converting a float to an int in Java, including:

  1. Typecasting: Using the` (int)` typecast operator, as shown in the previous answer, is the simplest method of converting a float to an int. However, it truncates any decimal component of the float, rather than rounding it.
  2. Math.round(): This method rounds a float value to the nearest integer and returns the result as a `long` data type. To convert the result to an int, you can use a typecast, such as `int myInt = (int) Math.round(myFloat);`
  3. DecimalFormat: This is a class in the Java library that allows you to specify a pattern for formatting numbers. You can use the `format()` method of the DecimalFormat class to convert a float to an int. For example, `int myInt = Integer.parseInt(new DecimalFormat(“0”).format(myFloat));`.
  4. Double to int conversion: Another approach is to first convert the float to a double, and then use a typecast to convert the double to an int. This method can be useful if the float value is too large to be stored as an int. For example, `int myInt = (int) (double) myFloat;`.

Approach 1 – Using the ‘(int)’ typecast operator.

The first approach to converting a float to an int in Java is the typecasting approach, using the `(int)` typecast operator. This operator converts a float value to an integer by truncating the decimal component of the float value and storing the result as an int data type.

The type casting operator runs in a single step and is performed immediately when encountered in the code. It takes the value stored in the float variable and applies the typecast operation, which discards the decimal component of the float and stores the result as an int.

It’s important to note that the typecast operator does not perform any rounding of the float value, so any decimal component will be lost during the conversion process. This can result in a loss of precision if the float value is not an exact integer.

In summary, the typecasting approach is a quick and simple method for converting a float to an int in Java, but it is not suitable for all cases and may result in a loss of precision.

Example: Using the ‘(int)’ typecast operator.

public class Main {
  public static void main(String[] args) {
//Create the float and define the parameter
    float myFloat = 3.14f;
//Define the typecast operator with desire format
    int myInt = (int) myFloat;

    System.out.println("Original float value: " + myFloat);
    System.out.println("Converted int value: " + myInt);
  }
}

Output:

Original float value: 3.14
Converted int value: 3

Explanation:

  1. The typecast operator `(int)` truncates the decimal component of the float value, resulting in an integer value of `3`.
  2. The original float value of `3.14` is stored as an int value of `3`.

Approach 2 – Using the `Math.round()` function.

The second approach to converting a float to an int in Java is the use of the `Math.round()` function. This function takes a float value as input and returns the closest integer value to that float, rounded to the nearest integer.

The `Math.round()` function runs in a single step and is performed immediately when encountered in the code. It takes the value stored in the float variable, rounds it to the nearest integer, and returns the result as a long data type. To convert the result to an int, you can then use the typecasting operator `(int)`.

In contrast to the typecasting approach, the `Math.round()` function performs rounding on the float value, so any decimal component will be taken into account during the conversion process. This makes the `Math.round()` function a more suitable choice when preserving the precision of the original float value is important.

In summary, the `Math.round()` function is a useful tool for converting a float to an int in Java, particularly when precision is important and you need to round the float value to the nearest integer.

Example: Using the `Math.round()` function.

public class Main {
  public static void main(String[] args) {
//Create the float and define the parameter
    float myFloat = 3.14f;
//Define the typecast operator with desire format
    int myInt = (int) Math.round(myFloat);
    System.out.println("Original float value: " + myFloat);
    System.out.println("Converted int value: " + myInt);
  }
}

Output:

Original float value: 3.14
Converted int value: 3

 Explanation:

  1. In this example, the `Math.round()` function is used to round the float value of `3.14` to the nearest integer.
  2. The result is then stored as an int value using the typecasting operator `(int)`.

The `Math.round()` function has rounded the float value up to the nearest integer, resulting in an int value of `3`.

Approach 3 – Using the ‘(int)’ type casting operator, in combination with the ‘Math.floor()’ functions

The third approach to converting a float to an int in Java is the use of the `(int)` typecasting operator, in combination with the `Math.floor()`functions. The `Math.floor()` function takes a float value as input and returns the largest integer value that is less than or equal to that float.

This function is executed in a single step when encountered in the code, and it work by first converting the float value to a double, then rounding it to the nearest integer. To convert the result to an int, you can then use the typecasting operator `(int)`.

In summary, the combination of the `(int)` typecasting operator with the `Math.floor()` functions provides another way to convert a float to an int in Java, by rounding the float to the nearest integer and converting the result to an int.

Example : Using the `(int)` typecasting operator, in combination with the `Math.floor()` functions

public class Main {
  public static void main(String[] args) {
//Create the float and define the parameter
    float myFloat = 3.14f;
//Define the typecast operator using Math.floor with desire format
    int myInt = (int) Math.floor(myFloat);
    System.out.println("myInt: " + myInt);
  }
}

Output:

myInt: 3

 Explanation:

  1. The `Math.floor()`  function used to round the float value to the nearest integer.
  2. The result is then converted to an int using the `(int)` typecasting operator.
  3. The output shows that the `Math.floor()` function rounds down the float to the nearest integer.

Approach 4 – Using the `(int)` type casting operator, in combination with the `Math.ceil()` functions

The next approach to converting a float to an int in Java is the use of the `(int)` typecasting operator, in combination with the `Math.ceil()` functions. The `Math.ceil()` function takes a float value as input and returns the smallest integer value that is greater than or equal to the float input.

And here’s an example of using the `Math.ceil()` function and the `(int)` typecasting operator to convert a float to an int in Java:

public class Main {
  public static void main(String[] args) {
//Create the float and define the parameter
    float myFloat = 3.14f;
//Define the typecast operator using Math.ceil with desire format
    int myInt = (int) Math.ceil(myFloat);
    System.out.println("myInt: " + myInt);
  }
}

Output:

myInt: 4

  Explanation:

  1. The `Math.ceil()` function used to round the float value to the nearest integer.
  2. The result is then converted to an int using the `(int)` typecasting operator.
  3. The output shows that the `Math.ceil()` function rounds up the float to the nearest integer.

Approach 5 – using a float to an int in Java is using the (int) typecasting operator –  int myInt = (int) (double) myFloat.

The fourth approach to converting a float to an int in Java is using the (int) typecasting operator. This operator can be used to explicitly cast a float value to an int, discarding the fractional part of the float value. The typecasting operator works by converting the float value to an int value. The fractional part of the float value is simply discarded, and the int value will contain only the rounded down integer portion of the float value.

This approach is straightforward and easy to use, but it is important to note that it can cause data loss if the float value has a large fractional component. The (int) typecasting operator does not round the float value; it simply discards the fractional part of the float value, so the resulting int value may not be what you expect if the float value is large.

Example – using a float to an int in Java is using the (int) typecasting operator –  int myInt = (int) (double) myFloat.

public class Main {
	public static void main(String[] args) {
//Create the float and define the parameter
		float myFloat = 3.14f;
//Define the typecast operator using (int) (double) myFloat 
		int myInt = (int) myFloat;
		System.out.println("myInt: " + myInt);
	}
}

Output:

myInt: 3

 Explanation:

  1. In this example, the float value `myFloat` is explicitly cast to an int value using the `(int)` typecasting operator.
  2. The fractional part of the float value is discarded, and the int value `myInt` contains only the rounded down integer portion of the float value.
  3. The output shows that the `myInt` value is 3, which is the rounded down integer portion of the float value `myFloat`

Best Approach for converting float to int in java:

The best approach to converting a float to an int in Java depends on the specific requirements and constraints of the situation. If you need to round the float value to the nearest integer, the `Math.round()` function is a good choice. If you need to truncate the float value and discard the fractional part, the `(int)` typecasting operator or the `Math.floor()` function are both good options.

In general, the `Math.round()` function is the best approach if you need to round the float value to the nearest integer, as it provides a clear and straightforward solution to this problem. The `(int)` typecasting operator is a good choice if you need to truncate the float value and discard the fractional part, as it is a simple and easy-to-use solution that is well-suited to this task. The `Math.floor()` function is also a good choice if you need to truncate the float value and discard the fractional part, as it provides a more flexible solution that can handle both positive and negative float values.

Sample Problems for converting Float to int in Java:

Sample Problem 1: Using the` (int)` typecast operator.

Write a program that takes a float value representing a person’s height in meters and converts it to an integer number of centimeters.

public class Main {
  public static void main(String[] args) {
//Create the float and define the parameter
    float heightInMeters = 1.75f;
//Define the typecast operator with desire format
    int heightInCentimeters = (int) (heightInMeters * 100);
    System.out.println("Person's height in centimeters: " + heightInCentimeters);
  }
}

Output:

Person's height in centimeters: 175

Explanation:

  1. In this problem, the float value representing the person’s height in meters is first multiplied by 100 to convert it to centimeters.
  2. The result is then stored as an int value using the typecasting operator (int). This demonstrates the use of the typecasting approach to convert a float to an int in a real-world scenario.

Sample Problem 2 – Using the `Math.round()` function.

Write a program that takes a float value representing a person’s body mass index (BMI) and converts it to an integer. The BMI is calculated as a person’s weight divided by the square of their height.

public class Main {
  public static void main(String[] args) {
//Create the float and define the parameter
	float weight = 72.5f;
	float height = 1.75f;
	float bmi = weight / (height * height);
//Define the typecast operator with desire format
	int roundedBmi = (int) Math.round(bmi);
	System.out.println("Person's BMI: " + roundedBmi);
  }
}

Output:

Person's BMI: 24

Explanation:

  1. In this problem, the float value representing the person’s BMI is first calculated and stored in the `bmi` variable.
  2. The `Math.round()` function is then used to round the `bmi` value to the nearest integer, and the result is stored as an int value using the typecasting operator `(int)`.
  3. This demonstrates the use of the `Math.round()` function to convert a float to an int in a real-world scenario.

Sample Problem 3 – Using the `(int)` typecasting operator, in combination with the `Math.floor()` or `Math.ceil()` functions

Write a program that calculates the square footage of a rectangular room and converts the result to an integer. The length and width of the room are given as float values.

public class Main {
  public static void main(String[] args) {
//Create the float and define the parameter
    float length = 12.5f;
    float width = 10.75f;
    float squareFootage = length * width;
//Define the typecast operator with desire format
    int roundedSquareFootage = (int) Math.floor(squareFootage);
    System.out.println("Square footage of the room: " + roundedSquareFootage);
  }
}

Output:

Square footage of the room: 134

Explanation:

  1. In this problem, the square footage of the room is calculated as the product of the length and width and stored in the `squareFootage` variable.
  2. The `Math.floor()` function is then used to round the `squareFootage` value down to the nearest integer, and the result is stored as an int value using the typecasting operator `(int)`.

This demonstrates the use of the combination of the `(int)` typecasting operator and the `Math.floor()` function to convert a float to an int in a real-world scenario.

Sample Problem 4 – using a float to an int in Java is using the (int) typecasting operator –  int myInt = (int) (double) myFloat.

Write a program that calculates the total number of apples a person has after buying some. The price of an apple and the amount of money the person has is given as a float. The program should calculate the total number of apples the person can buy and convert the result to an integer.

public class Main {
	public static void main(String[] args) {
//Create the float and define the parameter
		float pricePerApple = 0.75f;
		float money = 5.0f;
		float totalApples = money / pricePerApple;
//Define the typecast operator using (int) (double) myFloat 
		int roundedTotalApples = (int) totalApples;
		System.out.println("Total number of apples: " + roundedTotalApples);
	}
}

Output:

Total number of apples: 6

 Explanation:

  1. In this problem, the total number of apples the person can buy is calculated as the division of the amount of money by the price of an apple, and stored in the `totalApples` variable.
  2. The result is then cast to an int value using the `(int)` typecasting operator, discarding the fractional part of the float value, and stored in the `roundedTotalApples` variable.
  3. The final output shows the number of apples the person can buy as an integer.

Conclusion

In conclusion, there are four different approaches to convert a float to an int in Java: `Math.round()`, `(int)` typecasting operator, `Math.floor()`, and `Math.ceil()`. Each of these approaches has its own pros and cons and may be more suitable for different situations, depending on the specific requirements and constraints.

While `Math.round()` is the best approach if you need to round the float value to the nearest integer, the `(int)` typecasting operator is a good choice if you need to truncate the float value and discard the fractional part. The `Math.floor()` function is also a good choice if you need to truncate the float value and discard the fractional part, and the `Math.ceil()` function is a good choice if you need to round up the float value to the nearest integer.

Therefore, it is recommended to try out all the approaches before making a final decision, to determine which approach is the best for your specific needs.