Math Class in Java
In Java, the Math class is a part of the java.lang package and provides a wide range of mathematical methods and constants for performing common mathematical operations. It is a static class, which means you don’t need to create an instance of it; you can access its methods and properties directly.
Key Features of the Math Class:
Static Methods: The Math class comprises static methods for executing mathematical operations like trigonometric functions, exponentiation, logarithms, and more.
Mathematical Constants: It provides essential mathematical constants such as π (pi) and the base of the natural logarithm.
Common Methods of the Math Class:
Rounding and Absolute Value: Utilize methods like Math.round(), Math.floor(), and Math.abs() for rounding numbers and obtaining absolute values.
1. Math.round():
Purpose: Rounds a floating-point number to the nearest integer.
Usage: It rounds 0.5 and above upwards, and below 0.5 downwards.
Example:
long roundedValue = Math.round(4.7); // Returns 5
long roundedValue2 = Math.round(4.3); // Returns 4
2. Math.floor():
Purpose: Rounds a floating-point number down to the nearest integer, regardless of the decimal value.
Usage: Always rounds downward, even if the decimal is above 0.5.
Example:
double floorValue = Math.floor(4.7); // Returns 4.0
double floorValue2 = Math.floor(4.3); // Returns 4.0
3. Math.abs():
Purpose: Returns the absolute (positive) value of a number, removing any negative sign.
Usage: Works with both integers and floating-point numbers.
Example:
int absValue = Math.abs(-5); // Returns 5
double absValue2 = Math.abs(-4.7); // Returns 4.7
- Square Root: Calculate square roots using Math.sqrt().
- Min and Max Values: Find the minimum and maximum of two values using Math.min() and Math.max().
- Truncate Equivalent: In Java, you can use the Math.floor() method to remove the decimal part of a number. This method rounds the number down to the nearest whole number, even if the number is positive or negative. It always rounds toward negative infinity, meaning it rounds down.
Example
- For 10.3:
- Math.floor(10.3) will return 10.0, because it removes the decimal part and rounds down.
- For 10.7:
- Math.floor(10.7) will also return 10.0, because it rounds down to the nearest whole number.
Exponentiation: The Math.pow() method in Java is used to calculate a specified number raised to the power of another specified number.
Example:
1. Math.pow(2, 3): This means 2 raised to the power of 3, which is 23=2×2×2=82^3 = 2 \times 2 \times 2 = 823=2×2×2=8.
2. Math.pow(5, 2): This means 5 raised to the power of 2, which is 52=5×5=255^2 = 5 \times 5 = 2552=5×5=25.
Examples of Common Methods:
// Math.floor(): Rounds a number down to the nearest integer.
double weight = 10.75;
double floorWeight = Math.floor(weight);
System.out.println(floorWeight); // floorWeight is 10.0
// Math.max(): Returns the larger of two numbers.
double greaternumber = Math.max(10.5, 20.7);
System.out.println(greaternumber); // greaternumber is 20.7
// Math.min(): Returns the smaller of two numbers.
double smallernumber = Math.min(30.9, 15.3);
System.out.println(smallernumber); // smallernumber is 15.3
// Math.sqrt(): Calculates the square root of a number.
double squareRoot = Math.sqrt(64.0);
System.out.println(squareRoot); // squareRoot is 8.0
// Math.abs(): Returns the absolute (non-negative) value of a number.
double absWeight = Math.abs(-5.2);
System.out.println(absWeight); // absWeight is 5.2 the negative -5.2 is changes to positive value 5.2
// Math.round(): Rounds a number to the nearest integer.
long height = Math.round(7.6); if 7.4 show rule
System.out.println(height); // rounded number is 8
// Math.pow(): Raises a number to a specified power.
double result = Math.pow(2.0, 3.0); // 2^3 = 8
System.out.println(result); // result is 8.0
// Math.floor(): Removes the decimal part of a number (rounds towards negative infinity).
double truncatedHeight = Math.floor(8.9);
System.out.println(truncatedHeight); // truncatedHeight is 8.0
Tasks:
Write a program to round the following number to the nearest integer using Math.round.
Write a program to round the following number down to the nearest integer using Math.floor.
Write a program to get the absolute value of the following number using Math.abs.
Write a program to calculate the square root of the following number using Math.sqrt.
Write a program to find the maximum of the following two numbers using Math.max.
Write a program to find the minimum of the following two numbers using Math.min.
Write a program to remove the decimal part of the following number using Math.floor or Math.truncate.
Write a program to calculate 3 raised to the power of 4 using Math.pow.
Write a program that performs the following operations:
Rounds the number 5.8 to the nearest integer.
Finds the absolute value of -10.
Calculates the square root of 144.
Finds the maximum between 10 and 20.
Finds the minimum between 5 and 15.
Removes the decimal part of 9876.54321.
Raises 2 to the power of 5.
