Question

数组下标越界 java 问题 急

小弟新手
我要写一个类 关于array 的 但是出现数组下标越界

package assignment10;

//import java.util.Arrays;

public class StringArrayList {

private int capacity;

private String[] words;

private int elementCount;

/* This default constructor creates the array

*

*/

// problem how to hold 10 capacities

// how to null

public StringArrayList () {

words = new String[10];

elementCount = 0;

}

public void append (String s) {

if (elementCount == capacity)

{

// Grow the array.

String[] bigger = new String[capacity*2];

for (int i = 0; i < elementCount; i++)

{

bigger[i] = words[i];

}

capacity = bigger.length;

words = bigger;

}

// Add the element to the next available position

words[elementCount] = s;

elementCount++;

}

public void remove (int pos){

int count = words.length -1;

String [] temp = new String [count];

for(int i =0; i<= count; i++){

if (i<pos)

temp[i] = words[i];

else

temp[i] = words[i+1];

}

words =temp;

}
第一个 append 是添加 如果空间不足扩张2倍
第二个是删除 指定元素 然后它后面的元素会往前移 不如 1 2 3 4 5 我删了3 就变成 1 2 4 5 而不是 1 2 null 4 5. 谢谢各位大神

Answer 1

String[] bigger = new String[capacity*2];
capacity 是0，capacity*2还是0；
再用 words = bigger; 当然报异常