标识符举例 合法标识符 不合法标识符 FirstJavaApplet 1FirstJavaApplication MySalary 12 Tree&Glasses is True is True StheLastone Java builder HelloWorld 273.15 Java编译器检查非法标识符并报告语法错误标识符举例 合法标识符 不合法标识符 FirstJavaApplet 1FirstJavaApplication MySalary12 Tree&Glasses _ isTrue -isTrue _ $theLastOne Java Builder HelloWorld 273.15 Java编译器检查非法标识符并报告语法错误