摘要：
public class Calculator { public static void main(String[] args) { //为了避免magic number,采取定义变量 double n1, n2; n1 = 56; n2 = 65; System.out.println(calc( 阅读全文
摘要：
//StringBuilder class //java.lang.StringBuilder //methods: .append() .toString() // import java.util.Scanner; public class StrBuilder { public static 阅读全文