I decided to learn Spanish, just for fun.

我决定学习西班牙语，只是为了消遣。

《牛津词典》

I decided to learn Japanese just for fun.

我决定学日语只是为了好玩。

《牛津词典》

Just for fun, try it now.

只是为了好玩，现在就试试吧。

youdao

Well partly this is just for fun-- this is what computer people sometimes do, intentionally or unintentionally but as also will see a really nice way to culminate the semester and frankly carve out a 10 hour block where you can bite off your final project's implementation surrounded by friends and the course's staff.

一部分只是因为好玩-,这是懂电脑的人有时会这么做，不管有没有意义,还有一部分原因是因为,以这种方式达到学期的高潮,并在朋友和这门课程教师的关注下,抽出10小时的时间完成最终的项目安装,是一件多么美妙的事啊。

哈佛公开课 - 计算机科学课程节选

Just to amuse yourself, not for any kind of punitive think-about-the-exam exercise, but it would be fun to take these categories and think about these other countries, particularly those who were absolute states, other large important states in Europe and see to what extent you have these factors there.

我们可以做件有趣的事,纯粹为了娱乐,不是为了考试练习,即用同样的方法分析其他国家,特别是那些绝对主义国家,以及其他重要的欧洲大国,看看这些因素对政治结局的影响程度

耶鲁公开课 - 欧洲文明课程节选

And odds are if a week hence, two weeks hence just for fun you decide to reimplement your Scratch project -- or some tiny piece of it, it wouldn't be surprising -- or shouldn't be -- if you end of implementing the same game or animation or whatever using a completely different set of puzzle pieces Same deal we'd see here.

可能一周之后，两周之后，为了好玩,你决定重新实现你的Scrtch工程,或者其中一小部分，它将不会是令人惊讶的-,本来也不应该是--如果你运行相同的游戏,或者是动画，亦或是用完全不同的设置,来运行拼图游戏,我们将看到相同的处理。

哈佛公开课 - 计算机科学课程节选

The 5% Duma barrier was designed to weed out the just-for-fun contenders, but even the bigger ones have mutated, merged and divided like bacteria, leaving the voter bewildered.

ECONOMIST: The Russian elections

When the Obama team created We The People, they may not have thought too much about all the ridiculous and just-for-fun petitions that would reach the threshold and thus require a response (or maybe they did, and embraced it).

FORBES: We The People 2.0 And Why White House Petitions Matter

Kona, as it is known, is the full iron deal: a 2.4-mile swim, a 112-mile bike ride, and, just for fun, a complete marathon, 26.2 miles.

WSJ: Jason Gay: Italian for Dinner, a Triathlon for Dessert