操作符

• Its operators and expressions are similar to ordinary mathematical formulas
  它的操作符和表达式类似于普通的数学公式。
• Some of these are done with operators but most are done using methods
  其可以用操作符（执行动作）但更多的是使用方法。
• Methods are invoked as in the java language with the dot operator
  使用圆点( . )操作符调用方法（就像在java语言中一样） 。
• Provides links to topics covering changes to operators and file handling
  提供到包含对操作符和文件处理更改的主题的链接。
• Valid operators are
  有效的操作符是：
• Function call operator
  函数调用操作符
• Operator returns the ordinal position of an element within an array like the
  操作符返回对象在数组中的顺序位置类似xpath中的
• Operator follows a very strict set of rules to determine success or failure
  操作符遵循非常严格的一组规则来决定成功或失败。
• Expressions must not begin with an operator , comma , or closing parenthesis
  不可以用操作符、逗号或闭括号作为表达式的开始符。