20200910
Java程序的循行环境
书后习题
答案
一、课后检测
- 区分
- .java .class
- javac
- java + class文件名
- 二、基础编程
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system.out.print();
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8public class helloworld {
public static void main(String[] args) {
System.out.println("学号:20201020318");
System.out.println("姓名:张津瑞");
System.out.println("住所:大连");
System.out.println("电话:18114814418");
}
}
- (1)(2)
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5public class helloworld {
public static void main(String[] args) {
System.out.println("1"+ " "+"2"+ " "+"3"+ " "+"4"+ " ");
}
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8public class helloworld {
public static void main(String[] args) {
System.out.print("1"+" ");
System.out.print("2"+" ");
System.out.print("3"+" ");
System.out.print("4");
}
} - 编程挑战
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9public class helloworld {
public static void main(String[] args) {
System.out.println(" "+" "+"*");
System.out.println(" "+"*"+" "+"*"+" ");
System.out.println("*"+" "+" "+" "+"*");
System.out.println(" "+"*"+" "+"*"+" ");
System.out.println(" "+" "+"*");
}
}1
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43public class helloworld {
public static void main(String[] args) {
// 定义上部分输出的行数
int starLine = 3; //改变starLine的值输出不同大小的效果
// 1 输出上部分
for (int i = 1; i <= starLine; i++) {
// 1.1 输出左侧的空格
for (int j = 1; j <= starLine - i; j++) {
System.out.print(" ");
}
// 1.2 输出左侧的*
System.out.print("*");
// 1.3 输出中间的空格
for (int k = 2; k < 2 * i - 1; k++) {
System.out.print(" ");
}
// 1.4 输出右侧的*
if (i >= 2) {
System.out.print("*");
}
System.out.println();
}
// 2 输出下部分
for (int i = 1; i <= starLine - 1; i++) {
// 2.1 输出左侧的空格
for (int j = 1; j <= i; j++) {
System.out.print(" ");
}
// 2.2 输出左侧的*
System.out.print("*");
// 2.3 输出中间的空格
for (int k = 1; k <= (-2 * i + 2 * starLine - 3); k++) {
System.out.print(" ");
}
// 2.4输出右侧的*
if (i <= starLine - 2) {
System.out.print("*");
}
System.out.println();
}
}
}