java中肿么只用一个for和一个if打印来自菱形

以下是改写后的内容：
#问题：使用Java中的抽象类和接口来实现菱形图案打印
在Java中，我们可以使用抽象类和接口来实现菱形图案的打印。下面是一个示例代码：
```java
import java.util.Scanner;

public abstract class RhombicPatternPrinter {
protected int numColumns;
private int[] pattern;

public RhombicPatternPrinter(int numColumns) {
this.numColumns = numColumns;
pattern = new int[numColumns];
this.pattern = fillPattern();
}

@Override
public abstract void printPattern();

protected int[] fillPattern() {
int[] pattern = new int[4 * numColumns];
for (int i = 0; i < numColumns; i++) {
for (int j = i; j < i + 4; j++) {
if (j % 2 == i % 2) {
pattern[j / 2] += j / (2 * i);
} else {
pattern[j / 2] -= j / (2 * i);
}
}
}
return pattern;
}

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int numColumns = scanner.nextInt();
RhombicPatternPrinter printer;
if (numColumns % 2 == 0) {
printer = new SquarePatternPrinter(numColumns);
} else {
printer = new DiamondPatternPrinter(numColumns);
}
printer.printPattern();
scanner.close();
}
}

interface ShapeCalculator {
int calculate(int x, int y);
}

class SquarePatternPrinter implements RhombicPatternPrinter, ShapeCalculator {
private final int numColumns;

public SquarePatternPrinter(int numColumns) {
super(numColumns);
this.numColumns = numColumns;
}

@Override
public void printPattern() {
for (int i = 0; i < numColumns; i++) {
System.out.printf("%d*%d + %d*%d + %d*%d + %d*%d = %d
", i, i, i, i, i, i, i, i, i * (i + 1) / 2);
}
}

@Override
public int calculate(int x, int y) {
return x * y;
}
}

class DiamondPatternPrinter implements RhombicPatternPrinter, ShapeCalculator {
private final int numColumns;

public DiamondPatternPrinter(int numColumns) {
super(numColumns);
this.numColumns = numColumns;
}

@Override
public void printPattern() {
for (int i = numColumns / 2 - 2; i >= 1; i--) {
System.out.printf("%d*%d - %d*%d - %d*%d - %d*%d = %d
", i, i, i, i, i, i, i, i, i * (i - 1) / 2);
}
```

//先录入Scanner包
public static void main(String args[]){
for(;;){
System.out.print("请输入一个数1:);
Scanner in =new Scanner(System.in);
int a =in.nextInt();
System.out.print("/n请输入运算符:);
String fu=in.next();
System.out.print("/n请输入另一个数:);
int b =in.nextInt();
if (fu.equals("+")){
System.out.print("/n结果为:"+(a+b));
}else if(fu.equals("-")){
System.out.print("/n结果为:"+(a-b));
}else if(fu.equals("*")){

System.out.print("/n结果为:"+(a*b));
}else if(fu.equals("\")){

If (b==0){System.out.print("/n除数不可以为零");
}else{
System.out.print("/n结果为:"+(a\b));}
}else{
System.out.println("/n错误的符号")}
}
}

看不清楚，能否给个大图好看看。

这个问题很容易解决，jquery可以方便的实现，如下 ： <script type="text/javascript" src="jquery-1.4.2.min.js"></script> <script type="text/javasc360问答ript" src="jquery.PrintArea.js"></script> <script> $(document).的翻距做社升兵月ready(function(){ $("input#biuuu_button").click(function(){ $("div#myPrintArea").printArea(); }); }); </script> <input id="biuuu_button" type="button" value="打印"></input> <div id="myPrintArea">.....文本打印部分.....</div>

呵呵，这明显是一个上课的案例，这好像不是java的吧？你用多重if判断或者是swith case不就解决了？结果保留多少位小数就完了。