public class smp11 {
public static void main(String args[])
{
ko lkl = new ko();
lkl.intiko();
}
}
class score
{
int enGrade;
public void setEn(int enGrade)
{
this.enGrade=enGrade;
}
}
class ko
{
score stug[] = new score[3];
public void intiko()
{
stug[0].setEn(0);
stug[1].setEn(1);
stug[2].setEn(2);
}
}
创建了两个类,不知道为什么会出现异常,明明已经new了啊
------解决方案--------------------------------------------------------
- Java code
public class Smp11{ public static void main(String args[]) { Ko lkl = new Ko(); lkl.intiko(); } }class Score{ int enGrade; public void setEn(int enGrade) { this.enGrade = enGrade; }}class Ko{ Score stug[] = new Score[3]; public void intiko() { //需要先给数组中的元素赋值 stug[0] = new Score(); stug[1] = new Score(); stug[2] = new Score(); stug[0].setEn(0); stug[1].setEn(1); stug[2].setEn(2); }}
------解决方案--------------------------------------------------------
具体做法
- Java code
public class smp11 {public static void main(String args[]){ko lkl = new ko();lkl.intiko();}}class score{ int enGrade; public void setEn(int enGrade) {this.enGrade=enGrade; }}class ko{ score stug[] = new score[3]; public void intiko() { stug[0]=new score(); stug[1]=new score(); stug[2]=new score(); stug[0].setEn(0); stug[1].setEn(1); stug[2].setEn(2); }}
------解决方案--------------------------------------------------------
那是因为你没有实例化score.你定义了score为3的数组类型，却忽略了实例，必须报错，这样再实例一下就行了。
- Java code
public class smp11 { public static void main(String args[]) { ko lkl = new ko(); lkl.intiko(); } } class score { int enGrade; public void setEn(int enGrade) { this.enGrade=enGrade; } } class ko { int len=3; score[] stug = new score[len]; public void intiko() { for(int i=0;i<len;i++) { stug[i]=new score(); } stug[0].setEn(0); stug[1].setEn(1); stug[2].setEn(2); } }