The Java Library Concept in Java Programming.pptx

The Java Library Concept in Java Programming.pptx

• 1.
  JAVA LIBRARY Mrs.R.Chinthamani Assistant Professsor, Departmentof Computer Science E.M.G.Yadava Women’s College
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  Java libraries In javaprogramming, main two features are supported that is class and object. Basically we know that class is collection of objects and object is an instance of class. The uses of the java libraries of class spread the programmer efficiency by allowing computer programmer to focus on the functionality unique to their job.
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  Library Classes The javaprogrammer for developing their programming logic as well as their programming architecture with very smooth and very fine way. These classes are called Library Classes. In Java support thousands of library classes and also each class contains various types of functions.
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  Advantages of LibraryClasses in Java The type constraints are used to control where the java library classes can be replaced with routine versions without affecting type perfection of programs. Static analysis is then used to control those applicants for which unused library functionality and synchronization can be removed safely from the allocated types. The profile data is collected about the usage features of the customization candidates to determine where the allocation of custom library classes is likely to be cost-effective. To base on the static analysis results and the profiling information the custom library classes are automatically generated from a template. The bytecode of the client application is rewritten to use the generated
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  List of LibraryClasses in Java Library classes Purpose of the class Java.io Use for input and output functions. Java.lang Use for character and string operation. Java.awt Use for windows interface. Java.util Use for develop utility programming. Java.net Used for network communication. Java.math Used for various mathematical
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  Process to Input/ Output operation in JAVA: Java languages do not provide specific statement to input a value from the keyboard or to print the result on the visual display unit [VDU]. It uses the functions read() to accept a character from the keyboard and print() or println() to display the result on the screen.
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  Methods Summary: ClassMath Library classes function Purpose of the class abs(double a) Used to return the absolute value of the double value. abs(float a) Used to return the absolute value of the float value. abs(int a) Used to return the absolute value of an int value. abs(long a) Used to return the absolute value of a long value. acos(double a) Used to return the arc cosine of an angle, in the range of 0.0 through pi asin(double a) Returns the arc sine of an angle, in the range of −pi/2 through pi/2 atan(double a) Used to return the arc tangent of an angle, in the range of −pi/2 through pi/2
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  atan2(double y, doublex) Converts rectangular coordinates (x, y) to polar (r, theta) cbrt(double a) Used to return the cube root of a double value ceil(double a) Used to return the smallest (closest to negative infinity) double value that is greater than or equal to the argument and is equal to a mathematical integer cos(double a) Used to return the trigonometric cosine of an angle cosh(double x) Used to return the hyperbolic cosine of a double value exp(double a) Used to return Euler’s number e raised to the power of a double value expm1(double x) Used to return ex 1 − floor(double a) Used to return the largest (closest to positive infinity) double value that is less than or equal to the argument and is equal to a mathematical integer than or
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  hypot(double x, doubley) Used to return sqrt(x2 + y2) without intermediate overflow or underflow IEEEremainder(double f1, double f2) Computes the remainder operation on two arguments as prescribed by the IEEE 754 standard log(double a) Used to return the natural logarithm (base e) of a double value log10(double a) Used to return the base 10 logarithm of a double value log1p(double x) Used to return the natural logarithm of the sum of the argument and 1 max(double a, double b) Used to return the greater of two double values max(float a, float b) Used to return the greater of two float values max(int a, int b) Used to return the greater of two int values
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  max(long a, longb) Used to return the greater of two long values min(double a, double b) Used to return the smaller of two double values min(float a, float b) Used to return the smaller of two float values min(int a, int b) Used to return the smaller of two int values min(long a, long b) Used to return the smaller of two long values pow(double a, double b) Used to return the value of the first argument raised to the power of the second argument random() Used to return a double value with a positive sign, greater than or equal to 0.0 and less than 1.0. rint(double a) Used to return the double value that is closest in value to the argument and is equal to a mathematical integer
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  round(double a) Usedto return the closest long to the argument round(float a) Used to return the closest int to the argument signum(double d) Used to return the signum function of the argument; zero if the argument is zero, 1.0 if the argument is greater than zero, and 1.0 if the argument is less than − zero signum(float f) Used to return the signum function of the argument; zero if the argument is zero, 1.0f if the argument is greater than zero, and 1.0f if the argument is less − than zero sin(double a) Used to return the trigonometric sine of an angle
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  sqrt(double a) Used toreturn the correctly rounded positive square root of a double value tan(double a) Used to return the trigonometric tangent of an angle tanh(double x) Used to return the hyperbolic tangent of a double value toDegrees(double angrad) Converts an angle measured in radians into an approximately equivalent angle measured in degrees toRadians(double angdeg) Converts an angle measured in degrees into an approximately equivalent angle measured in radians ulp(double d) Used to return the size of an ulp of the argument ulp(float f) Used to return the size of an ulp of the argument
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  The Math Library Noneed to know how they are implemented. Contains constants such as E and PI. To access: Math.x or Math.m() , where x stands for the name of the constant / m for the name of the method you want to use
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  Math Library Examples Variabledeclaration double positiveNumber ; Variable initialiation double positiveNumber = Math.abs(-10);
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  For each methodit lists what the method needs as input and what it returns as output. SOME MORE EXAMPLES double twoCubed = Math.pow(2,3); double someTrigThingy = Math.sin(Math.PI);
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  How to Calla Static Method Syntax : Name of Class . Name of Method ( Parameter ) (Values for each Parameter , Separated by Commas) Parentheses are mandatory, even if there are no Parameters!
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  Method declaration usingSTATIC with MATH FUNCTIONS Key word (Static) Return Type , i.e. what the Method Produces as Output Name of the Metho d Method Paramete rs, i.e. What the Method requires as input Examples : static double sin(double a) static double sqrt(double a) static double pow(double a, double b) static int abs(int a) static int max(int a, int b)
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  Example Program forBoth STATIC MEMBER AND MATH LIBRARIES Class MathFunction { static float Mul (float x, float y) { return x * y ; } static float Divide (float x, float y) {
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  return x *y ; } } Class MathApplication { public static void main (string args [ ] ) { float a = MathFunction . Mul ( 4.0 , 5.0 ) ; float b = MathFunction . Divide ( a , 2.0 ) ; } }
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  OUTPUT : b =10.0
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  THANK YOU