public class Test{
   public static void main(String args[]){
           String data = " a bc   "; //调用string中的方法trim().length()方法         int trim = data.trim().length();         System.out.println("the trim length is "+trim); int length = data.length();         System.out.println("the length is "+length);     } }

 

显示:

the trim length is 4

the length is 8

trim()方法的作用是去掉字符串头尾的空格.