问题描述
package the_JC;
public class Cls_01 {
public static void main(String[] args) {
// Todo Auto-generated method stub
Stack1 obj1 = new Stack1(20);
for(int i = 1; i<=obj1.len; i++) {
obj1.push(i*3+i);
}
for(int i=0; i < obj1.len; i++) {
System.out.println(obj1.pop());
}
}
}
class Stack1{
int len=0;
Stack1(int num){
len = num;
System.out.println(len);
}
int[] stck = new int[len]; // this array is not accepting len as value from constructor above,taking len =0
int pos = -1;
void push(int value) {
System.out.println(stck.length);
if(pos==len-1) {
System.out.println("Overflowed");
} else {
stck[++pos] = value;
System.out.println("Pushed value :\t"+value);
}
}
int pop(){
if(pos<0) {
System.out.println("Underflow");
return 0;
} else {
return stck[pos--];
}
}
}
输出：
Exception in thread "main" java.lang.Arrayindexoutofboundsexception: Index 0 out of bounds for length 0
at the_JC/the_JC.Stack1.push(Cls_01.java:33)
at the_JC/the_JC.Cls_01.main(Cls_01.java:10)**
解决方法
class Stack1{
int len=0;
int[] stck;
int pos;
Stack1(int num){
len = num;
stck = new int[len];
pos = -1;
System.out.println(len);
}
void push(int value) {
System.out.println(stck.length);
if(pos==len-1) {
System.out.println("Overflowed");
} else {
stck[++pos] = value;
System.out.println("Pushed value :\t"+value);
}
}
int pop(){
if(pos<0) {
System.out.println("Underflow");
return 0;
} else {
return stck[pos--];
}
}
}