面试题：数组有没有length()方法？字符串有没有length()方法？集合有没有length()方法？

怼烎@ 2022-06-11 01:15 201阅读 0赞

数组求长度用length属性

字符串求长度用length()方法

集合求长度用size()方法

程序举例：

**\[java\]**  view plain  copy

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1.  package 集合.length\_size;  
2.    
3.  import java.util.ArrayList;  
4.  import java.util.List;  
5.    
6.  public class Length\_Size \{  
7.      public static void main(String\[\] args) \{  
8.          String\[\] strings = \{ "aaa","bbb","ccc"\};  
9.          String string = "aaabbbccc";  
10.         List<Integer> list = new ArrayList<Integer>();  
11.         list.add(1);  
12.           
13.         System.out.println("String\[\].length="\+strings.length);  
14.         System.out.println("String.length()="\+string.length());  
15.         System.out.println("List.size()="\+list.size());  
16.           
17.     \}  
18.   
19. \}

package 集合.length_size;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class Length_Size {
    	public static void main(String[] args) {
    		String[] strings = {"aaa","bbb","ccc"};
    		String string = "aaabbbccc";
    		List<Integer> list = new ArrayList<Integer>();
    		list.add(1);
    		
    		System.out.println("String[].length="+strings.length);
    		System.out.println("String.length()="+string.length());
    		System.out.println("List.size()="+list.size());
    		
    	}
    
    }