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Import keyword

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The import keyword makes one class or all classes in a package visible in the current Java source file. Imported classes can be referened without the use of fully−qualified class names.

Many Java programmers use only specific import statements (no '*') to avoid ambiguity when multiple packages contain classes of the same name.

import java.io.File;
import java.net.*;

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Implements Java Keyword

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The implements keyword is used in a class declaration to indicate that the class being declared provides implementations for all methods declared in the interface whose name follows the implements keyword.

In the example above, the Truck class must provide implementations for all methods declared in the IVehicle interface.

The Truck class is otherwise independent; it may declare additional methods and variables and may extend another class.

A single class may implement multiple interfaces.

public class Truck implements IVehicle
{
}

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if Java Keyword

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The if keyword indicates conditional execution of a block. The condition must evaluate to a boolean value.

An if statement may have an optional else clause containing code that is executed if the condition is false.

Expressions containing boolean operands can contain only boolean operands.

if (condition)
{

}
if (condition)
{

}
else
{

}

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For Keyword in Java

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The for keyword specifies a loop whose condition is checked before each iteration. Examples

The for statement takes the form for(initialize; condition; increment)

The initialize statement is executed once as the flow of control enters the for statement.

The condition is evaluated before each execution of the body of the loop. The body of the loop is executed if the condition is true.

The increment statement is executed after

int i;
for (i=0; i
}

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Float Java Keyword

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float Java Keyword float is a Java primitive type. A float variable may store a single−precision floating point value. ExamplesRemarks

The following rules apply to this keyword's use:

Floating point literals in Java always default to double−precision. To specify a single−precision literal value, follow the number with f or F, as in 0.01f.

Since floating point data types are approximations of real numbers, you should generally never compare floating point numbers for equality.

Java floating point numbers can represent infinity and NaN (not a number). The Float wrapper class defines the constants MIN_VALUE, MAX_VALUE, NEGATIVE_INFINITY, POSITIVE_INFINITY and NaN.

float ratio = .01;
float diameter = 6.15;
float height = 1.35E03; // 1.35 * 103 or 1350.0
float height = 1e−2; // 1.0 * 10−2 or 0.01

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Finally Java Keyword

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The finally keyword is used to define a block that is always executed in a try−catch−finally statement. A finally block typically contains cleanup code that recovers from partial execution of a try block. Examples Remarks

The opening and closing curly braces { and } are part of the syntax of the finally clause and may not be omitted even if the clause contains a single statement.

Every try block must have at least one catch or finally clause.

If any portion of the try block is executed, the code in a finally block is always guaranteed to be executed whether an exception occurs or not and independent of whether the try or catch blocks contain return, continue or break statements.

In the absence of exceptions, control flows through the try block and then into the finally block.

If an exception occurs during execution of the try block and the appropriate catch block contains a break, continue or return statement, control flows through the finally block before the break, continue or return occurs.

try
{

}
catch ( e)
{

}
finally
{

}