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And as you might expect, I'm going to then try and see if I can convert that into a float.
正如你希望的我要试着把他们转化为浮点数,等一等。
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C So here I'm declaring a variable called c, and I'm pretty much translating the formula from the slide using the characters on my keyboard to a floating point value.
这里我声明了一个变量，然后我把那个幻灯片上的公式,用键盘上的字符翻译成了,浮点数值。
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OK, says it says enter a float. I give it something that can be converted into a float, it says fine. I'm going to go back and run it again though. If I run it again, it says enter a float.
好了，看到他说输入一个浮点数,我输入它可以转换为浮点数的值,那没问题，我回过来再运行一遍,如果我再运行一遍。
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It just throws the decimal point away and that's because, again, these are ints and the answer intuitively should be a floating point value, but I need to be more specific.
它直接把小数点后面的数值丢弃掉了，因为，凭直觉，那些整型数和结果应该是一个浮点数据,但是我需要一个更精确的数值。
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I could generalize this pretty nicely. Imagine the same kind of idea where I want to simply say I want to take input of anything and try and see how to make sure I get the right kind of thing. I want to make it polymorphic.
对吧，我试着输入浮点数,我能更好的一般化它,想象下类似的想法，我需要输入些什么,然后看看输入的是否正确,我想使他更多元化些。
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Here I actually need to tell the computer, "Give me some bytes in ram in which to store a value, and that value's going to be a floating point value."
这里我的确需要告诉计算机，“给我一些字节内存,来存储一个值，那个值将是,浮点型的数值“
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0 >> David: Yeah, so I very deliberately changed this 9 to a 9.0 so that my math would actually be floating point math involving real numbers and not just integers.
>，大卫：是的，我故意地把9改成9,那样我的数学实际上就是浮点数的了,包括实数，不只是整数。
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And he quite correctly, because he's more senior than I am, more experienced than I am, said it's actually a good thing.
你可以用加法来加浮点数，他很明显是正确的，因为他比我年长些，比我更有经验些。
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Last thing to say is why would you want to have exceptions? Well, let's go back to that case of inputting a simple little floating point.
最后要讲的是为什么有异常处理？,回到输入一个简单的小浮点数的例子,如果我期望主要是。
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Second thing to notice, is that little piece of pseudo code is telling me things about values.
然后需要注意的是，这些伪代码告诉了一些关于值方面的事情,我需要一个浮点数。
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And in that case, in general lists, I need to figure out what's the access time.
一些浮点数，一些字符串，一些数组内部的数组，各种各样。
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The reason I want to point this out to you is, if we go back up to the kinds of data objects we started with, floats, ints, strings, they actually behave the same way.
我要为大家指出这一点的原因是，如果我们想一下以前讲过的,数据类型的种类，浮点数，整数，字符串，它们实际上有相同的行为方式。
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And that then let's me get to, basically, base this code. Having done that, height I simply call base with get float, I call height with get float, and do the rest of the work.
现在让我们看看这段代码，其实已经写好了，我简单的调用下，用来得到一个浮点数，再调用下，来得到另外一个浮点数，然后做剩下的工作就可以了。
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Need to get the base in. Second thing I want to do, I need to get the height, so I'm going to input a value for the height, also as a float, a floating point.
也就是输入底的值，第二件我想要做的，事情就是得到三角形的高,因此我会输入一个值作为三角形的高，同样也是一个浮点数。
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Could be ints, could be floats, could be a combination of things, some ints, some floats, some lists, some strings, some lists of lists, whatever.
但是我们知道数组内部的元素，可以是任何对象，可能是整数也可能是浮点数，也可能是对象的组合，一些整数。
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I can't rely on the user. I want to make sure I get a float in it, so how do I do that?
我想确保这儿我得到的是一个浮点数,我该怎么做呢？
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If I wanted to get full, real division, I should make one of them a float.
如果我想要得到真正的除法答案，我需要把他们之中的一个,变为浮点数类型。
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So a floating point value again is a number with a decimal point, so it depends.
一个浮点型数据就是一个,带小数点的数。
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- And then I divide by an int -- that's okay because so long as you have a float involved at some point early on, you're okay.
然后我除以一个整型数-,那是可以的因为现在为止，我们在之前已经,引入了一个浮点数，你是对的。
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Now, this is not the nicest way to do it but it'll work. I can look at the type of the value of base and compare it to the type of an actual float and see, are they the same?
这不是最好的办法但它确实有用,我可以得到底的值的类型然后,和一个真的浮点数的类型比比,看他们是不是一样？
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It means anybody using that little function get float doesn't have to worry about what's inside of it. So for example, I decide I want to change the message I print out, I don't have to change the function, I just pass in a different parameter.
这代表着用这个方法去获得浮点数,的任何人都不用担心具体的实现了,例如，如果我想改变下,显示的信息的话，我不必去改变方法，我传个不同的参数就可以了。
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Well I'm relying on the contract, if you like, that the manufacturer of square root put together, which is, if I know I'm giving it two floats, which I do because I make sure they're floats, the contract, if you like, of square root says I'll give you back a float.
好吧我能靠一些类似合约来保证，如果这么说你喜欢的话,其实就是当求平方根的方法,获得了两个我已经确认了是浮点数的数后,这个类似合约的东西就会保证，返回一个浮点数。
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So, a 32 bit of float gives you a bunch of precision.
2比特的浮点型数据精度更大。
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So if I were to solve this problem, here's the way I would do it. I would say, first thing I want to do, is I want to input a value for the base as a float.
如果我想要解决这个问题，这就是我要解决它的方式了，第一件我要做的事情就是要,输入一个浮点数作为三角形的底。
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GetFloating-- GetFloating-- GetFloat for a floating point number.
还有-,得到一个浮点型的数据，并赋给一个浮点型的指针。
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And again, if I just run this, just to show that it's going to do the right thing, it says enter base, I'm obnoxious, it says oops, wasn't a float, so we'll be nice about it and I enter a height, and it prints out what I expected. I just concatenated those strings together, by the way, at the end.
我再来运行下看是不是做对了,提示输入底，噢，它提示说不是浮点数，我很高兴，然后我输入一个,浮点数作为高度显示结果和我预期的相同,顺便说一句,我只是在最后把这些字符串连接起来了。
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I can't rely on Professor Guttag if I give this- if this code to him, I can't rely on him to type in a float. Actually I can, because he's a smart guy, but in general, I can't rely on the user-- I wouldn't do it right to see if you did.
当Guttag使用这段代码的时候-,我不能相信他一定会输入一个浮点数,实际上我能因为他很聪明，但是总体上来讲，别相信用户一定会按照规则来-,我会故意做错来试试你的程序的。
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It's defined in CS50's library; its sole purpose in life is to ask the user for a floating point value and return it.
它被定义在CS50的函数库中，它的唯一目的是,向用户询问一个浮点数的值，然后返回它。
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So this is something that we would call an integer, or an INT. And this is something we would call a floating point, or a float.
这是我们称之为integer的类型，或者INT，这是我们,称为浮点数的类型，或者浮点。
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Now if you look at that list, there is actually something I didn't seem to check, which is, I said I wanted a float stored in hyp.
看下上面的清单，实际上我还有一些东西忘了检查,也就是说hyp中存储的，应该是浮点数类型。
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