Posts tagged Self Study

File permission

If you type ls -l, you can see file permission like below. First letter indicates if it is a Directory. Next each group of three characters ...

Dead code

Dead code can never be executed (unreachable code), and it only affects dead variables (written, but never read again), that is, irrelevant to ...

Method Inlining

Inlining is an optimization performed by the Java Just-In-Time compiler. The compiler may decide to replace your function call with the body of ...

Pipe & Redirection

Pipe is used to pass output to another Program or Utility. thing1 | thing2 thing1’s output s will be passed to things2 Program or Utility. ...

Garbage Collection

Garbage Collector root Local variables in the main method The main thread Static variables of the main class Mark and Sweep Algorithm The ...

Java Memory Structure

Static memory (Method area) Method information and Field information. Global constants and other data generated by the compiler(e.g. info to ...

Java features

Java is Easy to write and more readable and eye catching. Java has a concise, cohesive set of features that makes it easy to learn and use. Most ...

[String] concat() vs. +

concat() and + both add up strings. It looks same, but + do one more step. As seen below, + will create string builder and append the strings ...

DHCP

DHCP stands for Dynamic Host Configuration Protocol. When DHCP assigns an IP address, it actually leases that connection identifier to the ...