Programming Articles - Page 2966 of 3366

To convert a String to a double type number in Java, use the Double.parseDouble() method.Here is our string.String str = "699.7e130";Let us now convert the above string to double.double val = Double.parseDouble(str);Example Live Demopublic class Demo {     public static void main(String args[]) {        String str = "699.7e130";        double val = Double.parseDouble(str);        System.out.println(val);     } }Output6.997E132

Let's say, we have a numeric value of type double and our task is to convert it into other numeric primitive data types. To perform this operation, we require explicit casting as double is the largest primitive datatype available in Java. The process of converting larger data type into smaller one is called as explicit casting, also known as narrowing casting. Data types are used to specify the type of values stored in different variables. In Java, there are 8 primitive data types, out of which 6 are numeric types, including double, float, int, long, byte, and short. Example Scenario ... Read More

The java.lang.Math class contains methods for performing basic numeric operations such as the trigonometry, logarithm, etc.The following are some of the methods.Sr.NoMethods & Description1static double abs(double a)This method returns the absolute value of a double value.2static float abs(float a)This method returns the absolute value of a float value.3static int abs(int a)This method returns the absolute value of an int value.4static long abs(long a)This method returns the absolute value of a long value.5static double acos(double a)This method returns the arc cosine of a value; the returned angle is in the range 0.0 through pi.6static double asin(double a)This method returns the arc ... Read More

Let’s say we have the following three values −double val1 = 15.546; double val2 = 25.87; double val3 = Math.PI;Let us now format these double-type numbers. Firstly, we are formatting Euler’s number with Math.exp(). After that, we have also evaluated log. The %.3f you can see here is what we used for formatting the numbers.System.out.printf("exp(%.3f) = %.3f%n", val1, Math.exp(val1)); System.out.printf("log = %.3f%n", val1, Math.log(val1));The following is an example where we have also shown other ways to format double in Java.Example Live Demopublic class Demo {    public static void main(String args[]) {       double val1 = 15.546;     ... Read More

The java.lang.Double.isNan() method returns true if the specified number is a Not-a-Number (NaN) value, false otherwise.Let’s say the following are our Double values.Double val1 = new Double(3/0.); Double val2 = new Double(0/0.);Now, we will use the isNan() method to check whether the number is a NaN or not.val1.isNaN(); val2.isNaN()The following is our final example.Example Live Demopublic class Demo {    public static void main(String args[]) {       Double val1 = new Double(3/0.);       Double val2 = new Double(0/0.);       System.out.println(val1.isNaN());       System.out.println(val2.isNaN());    } }Outputfalse true

The Double isInfinite() method returns true if this Double value is infinitely large in magnitude, false otherwise.Let’s say we have the following Double values.Double val1 = new Double(3/0.); Double val2 = new Double(0/0.);Use the isInfinite() method now. The return value is a boolean.val1.isInfinite(); val2.isInfinite();The following is the final example.Example Live Demopublic class Demo {    public static void main(String args[]) {       Double val1 = new Double(3/0.);       Double val2 = new Double(0/0.);       System.out.println(val1.isInfinite());       System.out.println(val2.isInfinite());    } }Outputtrue false

To convert double primitive type to a Double object, you need to use Double constructor.Let’s say the following is our double primitive.// double primitive double val = 23.78;To convert it to a Double object, use Double constructor.// Double object Double ob = new Double(val);Example Live Demopublic class Demo {    public static void main(String args[]) {       // double primitive       double val = 23.78;       // Double object       Double ob = new Double(val);       System.out.println(ob);    } }Output23.78

What is Floating Point Number? Floating point number formatting is the process of controlling how floating point numbers (numbers with decimal points) are displayed(printed in a program). For example, if we have a decimal number of 123.45678, the formatted number can be 123.457, 123.46, and 123.5 instead of that number. This makes the numbers easier to read and more consistent. The Floating point is just a number with decimal points. For example 1.2, 2.45 and 123.4 are the examples of the point numbers. It helps ensure the number of decimal places, making numerical data easier to read and maintaining a ... Read More

To check two float arrays for equality, use the Arrays.equals() method.In our example, we have the following two float arrays.float[] floatVal1 = new float[] { 3.2f, 5.5f, 5.3f }; float[] floatVal2 = new float[] { 3.2f, 5.5f, 5.3f };Let us now compare them for equality.if (Arrays.equals(floatVal1, floatVal2)) { System.out.println("Both are equal!"); }The following is an example wherein we compare arrays and with that also use == to check for other conditions.Example Live Demoimport java.util.Arrays; public class Demo {    public static void main(String args[]) {       float[] floatVal1 = new float[] { 3.2f, 5.5f, 5.3f };       ... Read More

To compare Java float arrays, use the Arrays.equals() method. The return value is a boolean. Let’s say we have the following float arrays −float[] floatVal1 = new float[] { 3.2f, 5.5f, 5.3f }; float[] floatVal2 = new float[] { 8.3f, 8.8f, 9.2f }; float[] floatVal3 = new float[] { 6.2f, 6.9f, 9.9f }; float[] floatVal4 = new float[] { 3.2f, 5.5f, 5.3f };To compare them, the Arrays.equals() method is to be used −Arrays.equals(floatVal1, floatVal2); Arrays.equals(floatVal2, floatVal3); Arrays.equals(floatVal3, floatVal4);The following is the complete example wherein we compare all the arrays −Example Live Demoimport java.util.Arrays; public class Demo {    public static void ... Read More