怎么用java打印菱形？

java打印菱形方法：

package circulationDemo

import java.util.Scanner

public class Test {

public static void main(String[] args) {

Scanner input = new Scanner(System.in)

System.out.println("请输入要打印的行数：")

int num = input.nextInt()

t1(num)// 正直角

split()

t2(num)// 倒直角

split()

t3(num)// 等腰三角

split()

t4(num)// 等腰倒三角++

split()

t5(num)// 等腰倒三角--

split()

t6(num)// 实心菱形

split()

t7(num)// 空心菱形(1)

split()

t8(num)// 空心菱形(2)

split()

t9(num)// 空心菱形(3)

}

private static void t9(int num) {

for (int k = 1 k <= num k++) {

for (int i = 1 i <= (num - k) i++) {

System.out.print(" ")

}

System.out.print("*")

for (int i = 1 i <= ((k - 2) * 2 + 1) i++) {

System.out.print(" ")

}

if (k != 1) {

System.out.print("*")

}

System.out.println()

}

for (int k = num-1 k >= 1 k--) {

for (int i = 1 i <= (num - k) i++) {

System.out.print(" ")

}

System.out.print("*")

for (int i = 1 i <= ((k - 2) * 2 + 1) i++) {

System.out.print(" ")

}

if (k != 1) {

System.out.print("*")

}

System.out.println()

}

}

private static void t8(int num) {

// 上半部分

for (int i = 1 i <= num i++) {

// 打印上半部分空格

for (int j = 1 j <= num - i j++) {

System.out.print(" ")

}

// 打印原本实心的*部分

for (int j = 1 j <= 2 * i - 1 j++) {

// 仅在一行的开头和末尾打印*

if (j == 1 || j == 2 * i - 1) {

System.out.print("*")

} else {

System.out.print(" ")

}

}

System.out.println()

}

// 下半部分

for (int i = 1 i <= num - 1 i++) {

for (int j = 1 j <= i j++) {

System.out.print(" ")

}

for (int j = 1 j <= 2 * (num - i - 1) + 1 j++) {

if (j == 1 || j == 2 * (num - i - 1) + 1) {

System.out.print("*")

} else {

System.out.print(" ")

}

}

System.out.println()

}

}

private static void t7(int num) {

// 打印上半部分

for (int i = 1 i <= num i++) {

// 打印空格

for (int j = 1 j <= (num - i) j++) {

System.out.print(" ")

}

// 打印*的个数

if (i == 1) {

System.out.print("*")

} else {

System.out.print("*")

// 打印菱形里的空格

for (int j = 1 j <= (2 * i - 3) j++) {

System.out.print(" ")

}

System.out.print("*")

}

System.out.println()

}

// 打印下半部分

for (int i = num - 1 i > 0 i--) {

// 打印空格

for (int j = 1 j <= (num - i) j++) {

System.out.print(" ")

}

// 打印*的个数

if (i == 1) {

System.out.print("*")

} else {

System.out.print("*")

// 打印菱形里的空格

for (int j = 1 j <= (2 * i - 3) j++) {

System.out.print(" ")

}

System.out.print("*")

}

System.out.println()

}

}

private static void t6(int num) {

// 上半部分

for (int i = 1 i <= num i++) {

for (int j = 1 j <= num - i j++) {

System.out.print(" ")

}

for (int j = 1 j <= 2 * i - 1 j++) {

System.out.print("*")

}

System.out.println()

}

// 下半部分

for (int i = 1 i <= num - 1 i++) {

for (int j = 1 j <= i j++) {

System.out.print(" ")

}

for (int j = 1 j <= 2 * (num - 1 - i) + 1 j++) {

System.out.print("*")

}

System.out.println()

}

}

private static void t5(int num) {

for (int i = num i > 0 i--) {

for (int j = 1 j <= num - i j++) {

System.out.print(" ")

}

for (int j = 1 j <= 2 * i - 1 j++) {

System.out.print("*")

}

System.out.println()

}

回答于 2022-12-14

for(i=1i<=4i++)

{

这个小的for是打印每一行前边的空格

for(j=1j<=4-ij++)

System.out.print(" ")

这个是打印星星的

for(j=1j<=2*i-1j++)

System.out.print("*")

这个是打印完一行的换行

System.out.println("")

}

下边的是一样的  只不过每一行的空格和星星数   和上边是翻过来的

for(i=1i<=3i++)

{

for(j=1j<=ij++)

System.out.print(" ")

for(j=1j<=7-2*ij++)

System.out.print("*")

System.out.println("")

}

java.sql.SQLException: 无效的列索引

无效的列索引

at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:111)

at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:145)

at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:207)

atoracle.jdbc.driver.OraclePreparedStatement.setStringInternal(OraclePreparedStatement.java:5328)

atoracle.jdbc.driver.OraclePreparedStatement.setString(OraclePreparedStatement.java:5320)

at untitled5.addreader1.validID(addreader1.java:128)

at untitled5.addreader1.jButton1_actionPerformed(addreader1.java:97)

at untitled5.addreader1_jButton1_actionAdapter.actionPerformed(addreader1.java:175)

at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)

at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)

at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)

at javax.swing.DefaultButtonModel.setPressed(Unknown Source)

at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)

at java.awt.Component.processMouseEvent(Unknown Source)

at javax.swing.JComponent.processMouseEvent(Unknown Source)

at java.awt.Component.processEvent(Unknown Source)

at java.awt.Container.processEvent(Unknown Source)

at java.awt.Component.dispatchEventImpl(Unknown Source)

at java.awt.Container.dispatchEventImpl(Unknown Source)

at java.awt.Component.dispatchEvent(Unknown Source)

at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)

at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source

at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)

at java.awt.Container.dispatchEventImpl(Unknown Source)

at java.awt.Window.dispatchEventImpl(Unknown Source)

at java.awt.Component.dispatchEvent(Unknown Source)

at java.awt.EventQueue.dispatchEvent(Unknown Source)

at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.run(Unknown Source)

代码：String driverName = "oracle.jdbc.OracleDriver"

Driver driver = (Driver) Class.forName(driverName).newInstance()

//连接数据库

Connection con = DriverManager.getConnection(

"jdbc:oracle:thin:@LONG:1521:orcl", "sysman", "tongfang")

PreparedStatement pstmt = con.prepareStatement(

" insert into reader values(?)")

pstmt.setString(1, str1)

pstmt.setString(2,str2)

pstmt.setString(3,str3)

pstmt.setString(4,str4)

ResultSet res = pstmt.executeQuery()

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