as3 study notes 1: the length of the array

1. var arr1:Array = ["1","2","3","4"];  
2. delete arr1[0];  
3. trace(arr1.length);  //Output 4 (although delete can delete elements in the array, it does not change the length of the array)  
4.   
5. var arr2:Array = ["1","2","3","4"];  
6. arr2.splice(0, 1);  
7. trace(arr2.length); //Output 3 (splice also changes the length of the array while deleting the elements of the array)  
8.   
9. var arr3:Array = [];  
10. trace(arr3.length); //output 0  
11. arr3[3] = 1;  
12. trace(arr3.length); //Output 4 (when the array elements are assigned in the way of square brackets + array subscript, the length of the array becomes the maximum subscript +1)  
13.   
14. var arr4:Array = [];  
15. arr4["字符串key"] = "xxxxx";  
16. trace(arr4.length); //Output 0 (string subscripting does not change the length of the array)  
17. arr4["5"] = "xxxxx";  
18. trace(arr4.length); //Output 6 (if the word string is a pure number, it will be treated as a number)  
19. arr4["010"] = "xxxxx";  
20. trace(arr4.length); //Output 6 (different from int("010")==10, the subscript of the array will not be converted to int(), the result of arr4["010"] = "xxxxx" is There is an additional key of "010" in arr4, and the length of arr4 remains unchanged)