java入门基础------String练习1

class 练习1    //模仿trim功能，去掉两端空格{public static void sop(String str){System.out.println(str);}public static void main(String[] args){String s1 = "  asdasd f efew  ";sop(mytrim(s1));}public static String mytrim(String str){int start=0, end=str.length()-1;while(start<=end && str.charAt(start)==' ')start++;while(start<=end && str.charAt(end)==' ')end--;return str.substring(start, end+1);}}