regular variable造句

例句与造句

1. What is the difference between a reference and a regular variable ? how do you pass by reference & why would you want to
   引用变量与普通变量之间有何区别？如何通过引用传值？在什么情况下会这样做？
2. It's difficult to find regular variable in a sentence. 用regular variable造句挺难的