版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/zjl199303/article/details/78661453
注意：
1.函数的作用是把一个功能代封装起来，已达到提高功能代码的复用性
2.函数定义好之后是需要调用才执行的
3.如果一个函数没有返回值返回给调用者，那么返回值类型必须是使用void标识
①错误写法：没有返回值 函数类型必须是void
class demo11 {
public static void main(String[] args){
getGrade(80);
}
public static
String getGrade(int score){
String grade = "";
if(score>=90&&score<=100){
grade = "A";
}else if(score>=80&&score<90){
grade = "B";
}else if(score>=70&&score<80){
grade = "C";
}else if(score>=60&&score<70){
grade = "D";
}else{
grade = "E";
}
System.out.println(grade);
}
}
②没有返回值的正确写法：
class demo11 {
public static void main(String[] args){
getGrade(80);
}
public static
void getGrade(int score){
String grade = "";
if(score>=90&&score<=100){
grade = "A";
}else if(score>=80&&score<90){
grade = "B";
}else if(score>=70&&score<80){
grade = "C";
}else if(score>=60&&score<70){
grade = "D";
}else{
grade = "E";
}
System.out.println(grade);
}
}
③有返回值的正确写法：
class demo11 {
public static void main(String[] args){
String result = getGrade(80);
System.out.println(result);
}
public static
String getGrade(int score){
String grade = "";
if(score>=90&&score<=100){
grade = "A";
}else if(score>=80&&score<90){
grade = "B";
}else if(score>=70&&score<80){
grade = "C";
}else if(score>=60&&score<70){
grade = "D";
}else{
grade = "E";
}
return grade;
}
}
