class English{
String english;
String chinese;
}
public class Englishtest {
public static void main(String[] args){
English e[]=new English[1];
e[0].english="apple";
e[0].chinese="苹果";
e[1].chinese="橙";
e[1].english="orange";
for(int i=0;i<1;i++){
System.out.println(e[0].chinese);
}
}
}
编译没有报错 但运行就出了nullpointerexception 求指教
String english;
String chinese;
}
public class Englishtest {
public static void main(String[] args){
English e[]=new English[1];
e[0].english="apple";
e[0].chinese="苹果";
e[1].chinese="橙";
e[1].english="orange";
for(int i=0;i<1;i++){
System.out.println(e[0].chinese);
}
}
}
编译没有报错 但运行就出了nullpointerexception 求指教
e[0] = new English(); //要先实例化
e[1] = new English();
English e[]=new English[2];//在后面加
e[0] = new English();e[1] = new English();
String english;
String chinese;
}public class Englishtest {
public static void main(String[] args) {
English e[] = new English[2];
e[0] = new English();
e[1] = new English();
e[0].english = "apple";
e[0].chinese = "苹果";
e[1].chinese = "橙";
e[1].english = "orange";
for (int i = 0; i < 1; i++) {
System.out.println(e[0].chinese);
}
}
}
大概跟一二楼的差不多,就是在定义数组之后,要实例化。
String english;
String chinese;
}public class Test {
public static void main(String[] args) {
English e[] = new English[2];
e[0] = new English();//对象的实例化
e[1] = new English();
e[0].english = "apple";
e[0].chinese = "苹果";
e[1].chinese = "橙";
e[1].english = "orange";
for (int i = 0; i < 1; i++) {
System.out.println(e[0].chinese);
}
}
}
对象只有在实例化以后才可以使用,楼主忘记实例化,所以会出现空指向异常