Ruby - 将字符串转换为浮点数返回 0.0
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Ruby - conversion string to float return 0.0
提问by user984621
In a variable is stored this value: $10.00And I need to get this 10.00
在一个变量中存储了这个值：$10.00我需要得到这个10.00
I've tried to convert this value to float:
我试图将此值转换为浮点数：
new_price = '%.2f' % (price.to_f)
but I get just 0.0.
但我得到了0.0。
What's wrong with that? I've tried also
那有什么问题？我也试过
price = price.strip
price[0]=""
new_price = '%.2f' % (price.to_f)
But even this didn't help me... where is a problem?
但即使这对我也没有帮助......哪里有问题？
Thanks
谢谢
回答by froderik
You need to remove the $first. The whole thing like this:
您需要删除第$一个。整个事情是这样的：
'%.2f' % '.00'.delete( "$" ).to_f
or
或者
'%.2f' % '.00'[1..-1].to_f
if you like density and may encounter non dollars.
如果你喜欢密度，可能会遇到非美元。
回答by Odysseus Ithaca
To set it in a variable:
要将其设置在变量中：
current_price= '%.2f' % '.00'.delete( "$" ).to_f
The more common error, is a value in the thousands where there's a comma in the string like: 10,000.00. The comma will cause the same truncation error, but the decimal won't, and many programmers won't even catch it (we don't even notice the comma anymore). To fix that:
更常见的错误是字符串中有逗号的千位值，例如：10,000.00。逗号会导致同样的截断错误，但小数不会，许多程序员甚至不会抓住它（我们甚至不再注意到逗号）。要解决这个问题：
current_price= '%.2f' % '10,000.00'.delete( "," ).to_f
回答by Jexoteric
Adding on to froderick's answer of:
添加到 froderick 的回答：
You need to remove the $ first. The whole thing like this:
您需要先删除 $ 。整个事情是这样的：
'%.2f' % '.00'.delete( "$" ).to_f
or
或者
'%.2f' % '.00'[1..-1].to_f
if you like density and may encounter non dollars. you need to format the code for output to ensure that you get two decimal places >with
如果你喜欢密度，可能会遇到非美元。你需要格式化输出的代码以确保你得到两个小数位 >with
You need to format your output string to ensure you get two decimal places.
您需要格式化输出字符串以确保获得两位小数。
puts "Current amount: #{format("%.2f", amount)}"
