开发程序过程中,经常需要实时知道某个变量的值,某个函数执行时间以及程序运行到哪里了,使用debugger会打断程序的执行,本例程提供了一个好的解决办法-development procedure, often need to know the value of a given variable, a function of time, and procedures for the implementation of the operation where the debugger will be