在 Java 语言中,switch语句是一个多分支选择语句,也叫开关语句。它可以根据一个整型表达式有条件地选择一个语句执行。
switch(变量名称或表达式)
{
case 判断常量1: { 程序段1; break ; }
case判断常量2: { 程序段2; break; }
……
case判断常量n: { 程序段n; break; }
[ default: { 程序段n + 1; } ]
}
switch语句的流程图如图所示:
输入以下程序:
package exp2;import javax. swing .*;
public class exp2_13 {
public static void main(String args[])
{
int 分数 = 82;
String grade;
switch (分数 / 10) {
case 10:
case 9:
grade = "优";
break;
case 8:
grade = "良";
break;
case 7:
grade = "中";
break;
case 6:
grade = "及格";
break;
default:
grade = "不及格";
}
JOptionPane.showMessageDialog(null, "成绩等级:" + grade);
System.exit(0);
}
}
package exp2;import javax.swing.*;
public class exp2_13 {
public static void main(String args[])
{
int 分数 = 82;
String grade;
switch (分数 / 10) {
case 10:
case 9:
grade = "优";
break;
case 8:
grade = "良";
break;
case 7:
grade = "中";
break;
case 6:
grade = "及格";
break;
default:
grade = "不及格";
}
JOptionPane.showMessageDialog(null, "成绩等级:" + grade);
System.exit(0);
}
}
package exp2;import javax.swing.*;
public class exp2_13 {
public static void main(String args[])
{
int 分数 = 90;
String grade;
switch (分数 / 10) {
case 10:
case 9:
grade = "优";
break;
case 8:
grade = "良";
break;
case 7:
grade = "中";
break;
case 6:
grade = "及格";
break;
default:
grade = "不及格";
}
JOptionPane.showMessageDialog(null, "成绩等级:" + grade);
System.exit(0);
}
}
运行程序如下: