摘要： public class Example4_18{public static void main(String args[]){char a[]={'a','b','c','D','E','F'};for(int i=0;i<a.length;i++){if(Character.isLowerCase(a[i])){a[i]=Character.toUpperCase(a[i]);}else if(Character.isUpperCase(a[i])){a[i]=Character.toLo 阅读全文