一段程式碼看懂Java各種變數的定義及呼叫
阿新 • • 發佈:2022-03-31
class Variable_test{
Variable_test(){}
String MemberVariable="I am a membervariable in Variable_test Class!";
static String StaticVariable="I am a staticvariable in Variable_test Class!";
public void say(){
String MemberVariable="I am a localvariable in Variable_test Class!";
System.out.println(MemberVariable);
System.out.println(this.MemberVariable);
System.out.println(Variable_test.StaticVariable);
System.out.println(Variable.StaticVariable_public);
Variable t=new Variable();
System.out.println(t.MemberVariable_public);
}
}
public class Variable {
static String StaticVariable_public="I am a staticvariable in public class!";
String MemberVariable_public="I am a membervariable in public class!";
public static void main(String[] args) {
Variable_test test=new Variable_test();
test.say();
}
}
有static關鍵詞的變數稱為類變數,又叫靜態變數,呼叫時可直接通過“類名.變數名”呼叫,該關鍵詞不能用在方法中。
無static關鍵詞的變數叫成員變數,又叫例項變數,呼叫時需要先例項化一個物件,再通過“物件名.變數名”呼叫。