The following code converts an array of strings to an array of floats:
以下代码将字符串数组转换为浮点数组:
a = ["4", "5.5", "6"]
a.collect do |value|
value.to_f
end
=> [4.0, 5.5, 6.0]
Why does the following return an array of strings instead of floats?
为什么以下返回一个字符串数组而不是浮点数?
b = [ ["0.0034", "-0.0244", "0.0213", "-0.099"],
["0.0947", "-0.1231", "-0.1363", "0.0501"],
["-0.0368", "-0.1769", "-0.0327", "-0.113"],
["0.0936", "-0.0987", "-0.0971", "0.1156"],
["0.0029", "-0.1109", "-0.1226", "-0.0133"] ]
b.each do |row|
row.collect do |value|
value.to_f
end
end
=> [["0.0034", "-0.0244", "0.0213", "-0.099"], ["0.0947", "-0.1231", "-0.1363", "0.0501"], ["-0.0368", "-0.1769", "-0.0327", "-0.113"], ["0.0936", "-0.0987", "-0.0971", "0.1156"], ["0.0029", "-0.1109", "-0.1226", "-0.0133"]]
Also, is there a better way to do this?
另外,有更好的方法吗?
1 个解决方案
#1
11
Because you're calling each on b instead of collect, you end up returning the original array instead of a newly created array. Here's the correct code (I prefer map to collect, but that's just me):
因为您在b而不是collect上调用每个,所以最终返回原始数组而不是新创建的数组。这是正确的代码(我更喜欢收集地图,但那只是我):
b.map{ |arr| arr.map{ |v| v.to_f } }
#1
11
Because you're calling each on b instead of collect, you end up returning the original array instead of a newly created array. Here's the correct code (I prefer map to collect, but that's just me):
因为您在b而不是collect上调用每个,所以最终返回原始数组而不是新创建的数组。这是正确的代码(我更喜欢收集地图,但那只是我):
b.map{ |arr| arr.map{ |v| v.to_f } }