正则表达式在空格之前插入逗号

Question

你如何在一个空格之前插入N个逗号到这个字符串,但不是在一个句号或另一个逗号之后？使用ruby或javascript.

Answer 1

一种选择:

>>> var str = "Lorem ipsum dolor sit amet consectetur adipiscing elit. Praesent mauris neque adipiscing nec malesuada id fermentum at eros. Curabitur eu neque nunc, et porta risus.";
>>> str.replace(/([^,.]) /g, '$1, ');
"Lorem, ipsum, dolor, sit, amet, consectetur, adipiscing, elit. Praesent, mauris, neque, adipiscing, nec, malesuada, id, fermentum, at, eros. Curabitur, eu, neque, nunc, et, porta, risus."

或者,您可以采用另一种方式来模仿负面的后视:

>>> var str = "Lorem ipsum dolor sit amet consectetur adipiscing elit. Praesent mauris neque adipiscing nec malesuada id fermentum at eros. Curabitur eu neque nunc, et porta risus.";
>>> str.replace(/([,.])? /g, function($0, $1) { return $1 ? $0 : ', '; });
"Lorem, ipsum, dolor, sit, amet, consectetur, adipiscing, elit. Praesent, mauris, neque, adipiscing, nec, malesuada, id, fermentum, at, eros. Curabitur, eu, neque, nunc, et, porta, risus."