Public(valid) static(valid) void(valid) main(invalid)ĭata types: Every variable has a type, every expression has a type and all types are strictly define more over every assignment should be checked by the compiler by the type compatibility hence java language is considered as strongly typed programming language. Which of the following are valid java keywords? 1. new, delete(invalid) //delete is not a keyword 10. instanceof, sizeOf(invalid) //sizeOf is not reserved keyword 9. finalize, synchronized(invalid) //finalize is a method in Object class 8. extends, implements, imports(invalid) //imports keyword is not available in java 7. byte, short, Integer, long(invalid) //here Integer is a wrapper class 6. goto, constant(invalid) //here constant is not reserved keyword 5. break, continue, return, exit(invalid) //exit is not reserved keyword 4.
throw, throws, thrown(invalid) //thrown is not available in java 3. final, finally, finalize (invalid) //here finalize is a method in Object class. Which of the following list contains only java reserved words ? 1. In java we have only new keyword but not delete because destruction of useless objects is the responsibility of Garbage Collection. All reserved words in java contain only lowercase alphabet symbols. Rule 4: java identifiers are case sensitive up course java language itself treated as case sensitive language. Rule 3: identifiers are not allowed to starts with digit. Rule 2: If we are using any other character we will get compile time error. Rules to define java identifiers: Rule 1: The only allowed characters in java identifiers are: 1) 2) 3) 4) 5) It may be class name, method name, variable name and label name.
Identifier : A name in java program is called identifier. Array variable assignments Types of variables o Primitive variables o Reference variables o Instance variables o Static variables o Local variables o Conclusions Un initialized arrays o Instance level o Static level o Local level Var arg method o Single Dimensional Array Vs Var-Arg Method Main method o 1.7 Version Enhansements with respect to main() Command line arguments Java coding standards o Coding standards for classes o Coding standards for interfaces o Coding standards for methods o Coding standards for variables o Coding standards for constants o Java bean coding standards Syntax for setter method Syntax for getter method o Coding standards for listeners To register a listener To unregister a listener Various Memory areas present inside JVM Array declaration, construction, initialization in a single line.Ħ. Array construction Multi dimensional array creation 4. Array declaration Single dimensional array declaration Two dimensional array declaration Three dimensional array declaration 3. Literals o Integral Literals o Floating Point Literals o Boolean literals o Char literals o String literals o 1.7 Version enhansements with respect to Literals Binary Literals Usage of _ (underscore)symbol in numeric literals 6.
Data types o Integral data types Byte Short Int long o Floating Point Data types o boolean data type o Char data type o Java is pure object oriented programming or not ? o Summary of java primitive data type 5. Reserved words o Reserved words for data types: (8) o Reserved words for flow control:(11) o Keywords for modifiers:(11) o Keywords for exception handling:(6) o Class related keywords:(6) o Object related keywords:(4) o Void return type keyword o Unused keywords o Reserved literals o Enum o Conclusions 4. Identifiers o Rules to define java identifiers: 3. Core Java with SCJP/ OCJP Notes By Durga SirĭURGASOFT, # 202,2 Floor,HUDA Maitrivanam,Ameerpet, Hyderabad - 500038, 040 – 64 51 27 86, 80 96 96 96 96, 9246212143 | Core Java with SCJP/ OCJP Notes By Durga Sir
0 kommentar(er)
