JAVA- String类练习

 1 public class TestTrim {
 2     public static void main(String Args[]){
 3         String str ="   My Test Trim      ";
 4         System.out.println(myTrim(str));
 5         
 6     }
 7     public static String myTrim(String str){
 8         char[] arr=str.toCharArray();
 9         //定义arr数组的开始与结束索引值
10         int startIndex=0;
11         int endIndex=arr.length-1;
12         //确定开始索引值
13         while(true){
14             if(arr[startIndex]==‘ ‘){
15                 startIndex++;
16             }else{
17                 break;
18             }
19         }
20         //确定结束索引值
21         while(true){
22             if(arr[endIndex]==‘ ‘){
23                 endIndex--;
24             }else{
25                 break;
26             }
27         }
28         return str.substring(startIndex, endIndex+1);
29         
30     }
31 }