我用java编一个科学计算器,运行时一按“等于号”(=)就报错,
来源:学生作业帮 编辑:搜搜考试网作业帮 分类:综合作业 时间:2024/07/14 16:53:32
我用java编一个科学计算器,运行时一按“等于号”(=)就报错,
--------------------Configuration:--------------------Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException:For input string:"9=" at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1224) at java.lang.Float.parseFloat(Float.java:422) at MyCalcular2.actionPerformed(MyCalcular2.java:113) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236) at java.awt.Component.processMouseEvent(Component.java:6038) at javax.swing.JComponent.processMouseEvent(JComponent.java:3260) at java.awt.Component.processEvent(Component.java:5803) at java.awt.Container.processEvent(Container.java:2058) at java.awt.Component.dispatchEventImpl(Component.java:4410) at java.awt.Container.dispatchEventImpl(Container.java:2116) at java.awt.Component.dispatchEvent(Component.java:4240) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916) at java.awt.Container.dispatchEventImpl(Container.java:2102) at java.awt.Window.dispatchEventImpl(Window.java:2429) at java.awt.Component.dispatchEvent(Component.java:4240) at java.awt.EventQueue.dispatchEvent(EventQueue.java:599) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160) at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)
Process completed.
//其中m是用户输进去的数值和符号,我用stringbuffer的append方法连起来的 String mm=String.valueOf(m); int p1=mm.indexOf("+"); int p2=mm.indexOf("-"); int p3=mm.indexOf("×"); int p4=mm.indexOf("÷"); if(p1!=-1){ p=p1; } else if(p3!=-1){ p=p3; }else if(p2!=-1){ p=p2; } else if(p4!=-1){ p=p4; }
--------------------Configuration:--------------------Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException:For input string:"9=" at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1224) at java.lang.Float.parseFloat(Float.java:422) at MyCalcular2.actionPerformed(MyCalcular2.java:113) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236) at java.awt.Component.processMouseEvent(Component.java:6038) at javax.swing.JComponent.processMouseEvent(JComponent.java:3260) at java.awt.Component.processEvent(Component.java:5803) at java.awt.Container.processEvent(Container.java:2058) at java.awt.Component.dispatchEventImpl(Component.java:4410) at java.awt.Container.dispatchEventImpl(Container.java:2116) at java.awt.Component.dispatchEvent(Component.java:4240) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916) at java.awt.Container.dispatchEventImpl(Container.java:2102) at java.awt.Window.dispatchEventImpl(Window.java:2429) at java.awt.Component.dispatchEvent(Component.java:4240) at java.awt.EventQueue.dispatchEvent(EventQueue.java:599) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160) at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)
Process completed.
//其中m是用户输进去的数值和符号,我用stringbuffer的append方法连起来的 String mm=String.valueOf(m); int p1=mm.indexOf("+"); int p2=mm.indexOf("-"); int p3=mm.indexOf("×"); int p4=mm.indexOf("÷"); if(p1!=-1){ p=p1; } else if(p3!=-1){ p=p3; }else if(p2!=-1){ p=p2; } else if(p4!=-1){ p=p4; }
![我用java编一个科学计算器,运行时一按“等于号”(=)就报错,](/uploads/image/z/731244-12-4.jpg?t=%E6%88%91%E7%94%A8java%E7%BC%96%E4%B8%80%E4%B8%AA%E7%A7%91%E5%AD%A6%E8%AE%A1%E7%AE%97%E5%99%A8%2C%E8%BF%90%E8%A1%8C%E6%97%B6%E4%B8%80%E6%8C%89%E2%80%9C%E7%AD%89%E4%BA%8E%E5%8F%B7%E2%80%9D%EF%BC%88%3D%EF%BC%89%E5%B0%B1%E6%8A%A5%E9%94%99%2C)
自己根据提示,找原因
java.lang.NumberFormatException: For input string: "9=" at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1224) at java.lang.Float.parseFloat(Float.java:422) at MyCalcular2.actionPerformed(MyCalcular2.java:113)
很明显,"9="不是数字
在MyCalcular2.java:113行
java.lang.NumberFormatException: For input string: "9=" at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1224) at java.lang.Float.parseFloat(Float.java:422) at MyCalcular2.actionPerformed(MyCalcular2.java:113)
很明显,"9="不是数字
在MyCalcular2.java:113行
我用java编一个科学计算器,运行时一按“等于号”(=)就报错,
用C编出一个科学计算器,至少同时实现五个数的+,-,*,/,简单的开方,平方等操作?
java编个计算器怎么在加入小数点
用c#编一个简易计算器的思路
求java大神!下面是一个用java表示图的程序(邻接表表示法);在运行的时候提示NullPointerExceptio
sina等于0.6用科学计算器怎么算a
科学计算器怎么用?
小弟我用Lingo编了一个旅行商问题的程序,可以运行,但结果不符合约束条件,
用JAVA写一个计算器 要求有图形界面.简单的加减乘除,不要小数点运算.
用java语言编写一个简单计算器,并要实验报告和步骤说明.
用JAVA编写一个计算器完成简单的加法、减法、除法和乘法操作.
JAVA计算器,小数相乘的错误~是double类型的问题?我怎么改才行?3*1.3都出错等于3.900000000000