Category Archives: Knowledge

xampp htdocs permission

change nobody to deamon http://www.computernetworkingnotes.com/ubuntu-12-04-tips-and-tricks/how-to-fix-permission-of-htdocs-in-ubuntu.html

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VM

vmware virtual box kvm (for linux)

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package & import

package need to be placed before import Q: Does importing all classes in a package make my object file (.class or .jar) larger?A: No, import only tells the compiler where to look for symbols. Q: Is it less efficient to … Continue reading

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jit

java bytecode is a intermediate code, not the native code, it need to be converted to native code in order to run it jit will convert bytecode to native code just-in-time (JIT) compilation, also known as dynamic translation, is compilation … Continue reading

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is stack only for method?

https://en.wikipedia.org/wiki/Call_stack call stack is a stack data structure that stores information about the active subroutines of a computer program for active method primary purpose of a call stack is to store the return addresses return address -> the location (address) of … Continue reading

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is primitive data moved from heap to stack?

http://stackoverflow.com/questions/22779145/java-primitive-data-type-on-stack-or-heap primitive variable belong to a object will be in heap it will load the value to the stack once the method is called

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reference variable vs. instance variable

reference variable Car mycar = new Car(); is the variable which hold the address of the instance instance variable class Car { String color;} mycar.color=”red”; color is the variable within the instance

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