Durga Sir Scjp Notes

It may be class name, method name, variable name and label name. Whenever we are trying to print any object reference internally toString method will be executed which is implemented by default to return the following. Of arguments such type of methods are called var-arg methods. For every array type corresponding classes are available but these classes are part of java language and not available to the programmer level.

We can resolve this problem by using collections. If we want to represent real numbers then we should go for floating point data types. The main objective of command line arguments are we can customize the behavior of the main method. If we are taking array size with -ve int value then we will get runtime exception saying NegativeArraySizeException. It is a final method applicable for String objects.

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Which of the following are valid java identifiers? In java some identifiers are reserved to associate some functionality or meaning such type of reserved identifiers are called reserved words. You're using an out-of-date version of Internet Explorer.

It is legal to have an array with size zero in java. Return type should not be void. We can call or invoke this method by passing any no. Of int values including zero number also. Every array in java is an object hence we can create by using new operator.

Remember me on this computer. We can perform declaration, construction and initialization of an array in a single line. The allowed data types to specify array size are byte, short, char, int.

Any sequence of characters with in double quotes is treated as String literal. Create several problems in old languages and hence it is banned in java.

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We have to declare such type of variables at class level by using static modifier. Objects and corresponding instance variables will be stored in Heap area. Every entry in stack is called Stack Frame or Action Record. Whenever int is not enough to hold big values then we should go for long data type.

Not applicable but allowed values are true or false. It returns the no of characters present in the String. It represents the size of the array.

The order of modifiers is not important that is instead of public static we can take static public. In java we have only new keyword but not delete because destruction of useless objects is the responsibility of Garbage Collection. No case, in all the cases we will get runtime exception.


Second variable onwards we can't apply in the same declaration. Every variable in java should be either instance or static or local. Wherever var-arg parameter present we can't replace with single dimensional array. For the int type arrays the allowed array element types are byte, short, char, the one that got away music video int.

Literal value should be prefixed with zero. But recommended to use is.

We can't use reserved words as identifiers. All reserved words in java contain only lowercase alphabet symbols. Reference variables can be used to refer objects.

Full Core Java Tutorials By Durga Sir Notes Basic Java

Every escape character in java acts as a char literal. All the above data types byte, short, int and long can be used to represent whole numbers. For the integral data types byte, short, int and long we can specify literal value in the following ways. Java is pure object oriented programming or not? Native method invocations will be stored in native method stacks.

If we are not declaring any modifier explicitly then it means default modifier but this rule is applicable only for static and instance variables but not local variable. Compulsory it should take some argument. For the var-arg methods we can provide the corresponding type array as argument.

The main advantage of this approach is to improve memory utilization. If we are not satisfied with those default values then we can replays with our customized values.

This is most commonly used data type in java. Floating point literal is by default double type but we can specify explicitly as float type by suffixing with f or F. Static variables should be declared with in the class directly but outside of any method or block or constructor.

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All predefined java class names and interface names we use as identifiers. For every object a separate copy of instance variable will be created whereas for entire class a single copy of static variable will be created. Use final instead of this. Which of the following declarations are valid? None of the above valid Which of the following are valid java keywords?

Full Core Java Tutorials By Durga Sir Notes Basic Java

Even though above syntax is very strict but the following changes are acceptable to main method. Total how many objects created? For every Thread a separate copy of local variable will be created. The main advantage of arrays is we can represent multiple values with the same name so that readability of the code will be improved. Which of the following var-arg method declarations are valid?

Wherever single dimensional array present we can replace with var-arg parameter. Class level binary data includung static variables will be stored in method area. The only applicable modifier for local variables is final. In the case of primitive array as array element any type is allowed which can be promoted to declared type.

Instead of args we can use any valid java identifier. Which of the following list contains only java reserved words?