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This example shows how to copy the contents of one file into another file using read & write methods of FileStreams classes.ExampleLive Demoimport java.io.*; public class Main { public static void main(String[] args) throws Exception { BufferedWriter out1 = new BufferedWriter(new FileWriter("srcfile")); out1.write("string to be copied"); out1.close(); InputStream in = new FileInputStream(new File("srcfile")); OutputStream out = new FileOutputStream(new File("destnfile")); byte[] buf = new byte[1024]; int len; while ((len = in.read(buf)) > 0) { ... Read More
In case of having the operation of integer values in Java, we need to be aware of int underflow and overflow conditions. Considering the fact that in Java, The int data type is a 32-bit signed two's complement integer having a minimum value of -2, 147, 483, 648 and a maximum value of 2, 147, 483, 647. If a value goes beyond the max value possible, the value goes back to minimum value and continue from that minimum. In a similar way, it happens for a value less than the min value. Consider the following example.ExampleLive Demopublic class Tester { ... Read More
A Binary Relationship is the relationship between two different Entities i.e. it is a relationship of role group of one entity with the role group of another entity.There are three types of cardinalities for Binary Relationships −1. One-to-One2. One-to-many3. Many-to-ManyOne-to-OneHere one role group of one entity is mapped to one role group of another entity. In simple terms one instance of one entity is mapped with only one instance of another entity.In this type the primary key of one entity must be available as foreign key in other entity.For example − consider two entities Person and Driver_License.Person has the information about ... Read More
In a Relationship, Participation constraint specifies the existence of an entity when it is related to another entity in a relationship type. It is also called minimum cardinality constraint.This constraint specifies the number of instances of an entity that can participate in a relationship type.There are two types of Participation constraint −Total ParticipationEach entity in the entity set is involved in at least one relationship in a relationship set i.e. the number of relationship in every entity is involved is greater than 0.Consider two entities Employee and Department related via Works_For relationship. Now, every Employee works in at least one ... Read More
The java.lang.Enum class is the common base class of all Java language enumeration types.Class DeclarationFollowing is the declaration for java.lang.Enum class -public abstract class Enum extends Object implements Comparable, SerializableWe can compare enum variables using the following ways.Using Enum.compareTo() method. compareTo() method compares this enum with the specified object for order.Using Enum.equals() method. equals() method returns true if the specified object is equal to this enum constant.Using == operator. The == operator checks the type and makes a null-safe comparison of the same type of enum constants.ExampleLive Demopublic class Tester { // enum showing topics ... Read More
When we assigned an int to Integer object, it is first converted to an Integer Object and then assigned. This process is termed as autoboxing. But there are certain things which you should consider while comparison of such objects using == operator. See the below example first.ExampleLive Demopublic class Tester { public static void main(String[] args) { Integer i1 = new Integer(100); Integer i2 = 100; //Scenario 1: System.out.println("Scenario 1: " + (i1 == i2)); Integer i3 = ... Read More
If we compare a float and a double value with .5 or .0 or .1235 (ending with 5 or 0), then == operator returns true, otherwise it will return false. See the below example.ExampleLive Demopublic class Tester { public static void main(String[] args) { double d1 = 2.5; float f1 = 2.5f; System.out.println(d1 == f1); double d2 = 2.4; float f2 = 2.4f; System.out.println(d2 == f2); } }Outputtrue falseThe reason behind this logic is the approximation of float and ... Read More
Let us look at a simple code first that will print the words Hello World.ExampleLive Demopublic class MyFirstJavaProgram { /* This is my first java program. * This will print 'Hello World' as the output */ public static void main(String []args) { System.out.println("Hello World"); // prints Hello World } }Let's look at how to save the file, compile, and run the program. Please follow the subsequent steps −Open notepad and add the code as above.Save the file as: MyFirstJavaProgram.java.Open a command prompt window and go to ... Read More
The Assignment OperatorsFollowing are the assignment operators supported by Java language −OperatorDescriptionExample=Simple assignment operator. Assigns values from right side operands to left side operand.C = A + B will assign value of A + B into C+=Add AND assignment operator. It adds right operand to the left operand and assigns the result to left operand.C += A is equivalent to C = C + A-=Subtract AND assignment operator. It subtracts the right operand from the left operand and assigns the result to left operand.C -= A is equivalent to C = C � A*=Multiply AND assignment operator. It multiplies right ... Read More
Use the d-flex class in Bootstrap to create a flexbox container.Here, I have set two flex items − One Two You can try to run the following code to implement the .d-flex class −ExampleLive Demo Bootstrap Example Understanding Flex One Two