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