“如果"和“如果"有什么区别?带有“then"的语句在最后?

本文介绍了“如果"和“如果"有什么区别?带有“then"的语句在最后?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

当我们在 if 语句的末尾放置一个 then 时，这两个 Ruby if 语句之间有什么区别?

What's the difference between these two Ruby if statements when we put a then at the end of the if statement?

if(val == "hi") then something.meth("hello") else something.meth("right") end

和

if(val == "hi") something.meth("hello") else something.meth("right") end

推荐答案

then 是一个分隔符，帮助 Ruby 识别条件和表达式的真实部分.

then is a delimiter to help Ruby identify the condition and the true-part of the expression.

if 条件 then true-part else false-part end

if condition then true-part else false-part end

then 是可选的除非您想在一行中编写一个 if 表达式.对于跨越多行的 if-else-end，换行符作为分隔符将条件与真实部分分开

then is optional unless you want to write an if expression in one line. For an if-else-end spanning multiple lines the newline acts as a delimiter to split the conditional from the true-part

# can't use newline as delimiter, need keywords puts if (val == 1) then '1' else 'Not 1' end # can use newline as delimiter puts if (val == 1) '1' else 'Not 1' end