一、 程序的结构:
一般来说程序的结构包含有下面三种：
二、顺序结构
程序至上而下逐行执行，一条语句执行完之后继续执行下一条语句，一直到程序的末尾
aaarticlea/png;base64,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" alt="" width="287" height="167" />
三、选择结构
3.1 、IF语句--单分支结构
示例一、 比较2个整型变量的大小
package pb.test;
public class test4 {
public static void main(String[] args) {
int x = 3;
int y = 10; //定义2个整型变量，x,y
System.out.println("=======开始比较=======");
if(x>y){
System.out.println("x比y大!");
}
if(x<y){
System.out.println("x小于y!");
}
if(x==y){
System.out.println("x等于y!");
}
System.out.println("=======比较完成=======");
}
}
3.2、if...else语句--双分支结构
示例二、判断一个数字是奇数还是偶数
package pb.test;
public class test5 {
public static void main(String[] args) {
int x=3; //定义大中型变量x
if(x%2==0){ //如果余数为0则是偶数
System.out.println("x是偶数");
}else{ //如果余数不为0则是奇数
System.out.println("x是奇数");
}
}
}
3.3、三目运算符
示例三、求出2个数字中的最大值
public static void main(String[] args) {
//定义变量来保存最大值
int max=0;
//定义2个变量
int x=3;
int y=10;
//使用3目运算判断如果x>y则，max=x,否则max=y;
max=x>y?x:y;
System.out.println("max为: "+max);
}
3.4、if…else if…else语句 --多分支结构
示例四、
package pb.test;
public class test6 {
public static void main(String[] args) {
int x=3;
if(x==1){
System.out.println("x的值是1!");
}else if(x==2){
System.out.println("x的值是2!");
}else if(x==3){
System.out.println("x的值是3!");
}else{
System.out.println("x的值不是1，2，3 中的一个!");
}
}
}
四、Switch结构
4.1、执行流程
aaarticlea/png;base64,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" alt="" />
示例五、判断学生成绩，并给于评分，90~100分，A级大于80分，B级，大于70分，输出C级，大于60分，D级，低于60分输出E级
package pb.test;
public class test7 {
public static void main(String[] args) {
int score = 75; //声明学生分数
switch (score/10){
case 10:
case 9:
System.out.println("A级");
break;
case 8:
System.out.println("B级");
break;
case 7:
System.out.println("C级");
break;
case 6:
System.out.println("D级");
break;
default:
System.out.println("E级");
break;
}
}
}
结果:C级
还是上面的如果不加break;
package pb.test;
public class test7 {
public static void main(String[] args) {
int score = 75; //声明学生分数
switch (score/10){
case 10:
case 9:
System.out.println("A级");
case 8:
System.out.println("B级");
case 7:
System.out.println("C级");
case 6:
System.out.println("D级");
default:
System.out.println("E级");
}
}
}
结果：C级,D级,E级