log4j,slf4j, logback, log4j2등 java logger에 대해 정리해 보자

jenv를 설치, 사용해보자

import static java.lang.Math.*; abs System.out.println(abs(-34.5)); // 34.5 ceil System.out.println(ceil(2.17)); // 3.0 floor System.out.println( ...

Know your primitive types AND(&) if both bits are 1, it gives 1, else it gives 0. System.out.println(Integer.toBinaryString(6)); // 110 System.out.println(Integer.toBinar ...

Java basic type data structures