In Ruby language, how can I get the number of lines in a string?
在Ruby语言中，如何获取字符串中的行数？
6 个解决方案
#1
50
There is a lines method for strings which returns an Enumerator. Call count on the enumerator.
返回枚举器的字符串有一个line方法。调用者的呼叫计数。
str = "Hello\nWorld"
str.lines.count # 2
str = "Hello\nWorld\n" # trailing newline is ignored
str.lines.count # 2
The lines method was introduced in Ruby 1.8.7. If you're using an older version, checkout the answers by @mipadi and @Greg.
lines方法在Ruby 1.8.7中引入。如果您使用的是旧版本，请查看@mipadi和@Greg的答案。
#2
5
One way would be to count the number of line endings (\n or \r\n, depending on the string), the caveat being that if the string does not end in a new line, you'll have to make sure to add one to your count. You could do so with the following:
一种方法是计算行结尾的数量（\ n或\ r \ n，取决于字符串），需要注意的是，如果字符串没有以新行结尾，则必须确保添加一个到你的数量。您可以使用以下内容执行此操作：
c = my_string.count("\n")
c += 1 unless c[-1,1] == "\n"
You could also just loop through the string and count the lines:
你也可以循环遍历字符串并计算行数：
c = 0
my_string.each { |line| c += 1 }
Continuing with that solution, you could get really fancy and use inject:
继续使用该解决方案，您可以获得真正的幻想并使用注入：
c = my_string.each.inject(0) { |count, line| count += 1 }
#3
4
string".split("\n").size works nicely. I like that it ignores trailing new-lines if they don't contain content.
字符串“.split（”\ n“）。size非常适合。我喜欢它忽略了尾随的新行，如果它们不包含内容。
"Hello\nWorld\n".split("\n") # => ["Hello", "World"]
"hello\nworld\nfoo bar\n\n".split("\n").size # => 3
That might not be what you want, so use lines() as @Anurag suggested instead if you need to honor all new-lines.
这可能不是你想要的，所以如果需要尊重所有新行，请使用@Anurag建议的lines（）。
"hello\nworld\nfoo bar\n\n".lines.count # => 4
#4
1
"hello\nworld\nfoo bar\n\n".chomp.split("\n",-1).size # => 4
“你好\ nworld \ n \ nfoo bar \ n \ n”.chomp.split（“\ n”， - 1）.size＃=> 4
String#chomp gets rid of an end of line if it exists, and the -1 allows empty strings.
String＃chomp如果存在则删除行尾，-1允许空字符串。
#5
1
given a file object (here, in rails)
给定一个文件对象（这里，在rails中）
file = File.open(File.join(Rails.root, 'lib', 'file.json'))
file.readlines.count
returns the number of lines
返回行数
IO#readlines performs a split method on strings (IOStrings in this case) using newlines as the separator
IO＃readlines使用换行符作为分隔符对字符串（在本例中为IOStrings）执行拆分方法
#6
1
This will not count blank lines:
这不会算空行：
string.split("\n").select{ |line| line != "" }.size
#1
50
There is a lines method for strings which returns an Enumerator. Call count on the enumerator.
返回枚举器的字符串有一个line方法。调用者的呼叫计数。
str = "Hello\nWorld"
str.lines.count # 2
str = "Hello\nWorld\n" # trailing newline is ignored
str.lines.count # 2
The lines method was introduced in Ruby 1.8.7. If you're using an older version, checkout the answers by @mipadi and @Greg.
lines方法在Ruby 1.8.7中引入。如果您使用的是旧版本，请查看@mipadi和@Greg的答案。
#2
5
One way would be to count the number of line endings (\n or \r\n, depending on the string), the caveat being that if the string does not end in a new line, you'll have to make sure to add one to your count. You could do so with the following:
一种方法是计算行结尾的数量（\ n或\ r \ n，取决于字符串），需要注意的是，如果字符串没有以新行结尾，则必须确保添加一个到你的数量。您可以使用以下内容执行此操作：
c = my_string.count("\n")
c += 1 unless c[-1,1] == "\n"
You could also just loop through the string and count the lines:
你也可以循环遍历字符串并计算行数：
c = 0
my_string.each { |line| c += 1 }
Continuing with that solution, you could get really fancy and use inject:
继续使用该解决方案，您可以获得真正的幻想并使用注入：
c = my_string.each.inject(0) { |count, line| count += 1 }
#3
4
string".split("\n").size works nicely. I like that it ignores trailing new-lines if they don't contain content.
字符串“.split（”\ n“）。size非常适合。我喜欢它忽略了尾随的新行，如果它们不包含内容。
"Hello\nWorld\n".split("\n") # => ["Hello", "World"]
"hello\nworld\nfoo bar\n\n".split("\n").size # => 3
That might not be what you want, so use lines() as @Anurag suggested instead if you need to honor all new-lines.
这可能不是你想要的，所以如果需要尊重所有新行，请使用@Anurag建议的lines（）。
"hello\nworld\nfoo bar\n\n".lines.count # => 4
#4
1
"hello\nworld\nfoo bar\n\n".chomp.split("\n",-1).size # => 4
“你好\ nworld \ n \ nfoo bar \ n \ n”.chomp.split（“\ n”， - 1）.size＃=> 4
String#chomp gets rid of an end of line if it exists, and the -1 allows empty strings.
String＃chomp如果存在则删除行尾，-1允许空字符串。
#5
1
given a file object (here, in rails)
给定一个文件对象（这里，在rails中）
file = File.open(File.join(Rails.root, 'lib', 'file.json'))
file.readlines.count
returns the number of lines
返回行数
IO#readlines performs a split method on strings (IOStrings in this case) using newlines as the separator
IO＃readlines使用换行符作为分隔符对字符串（在本例中为IOStrings）执行拆分方法
#6
1
This will not count blank lines:
这不会算空行：
string.split("\n").select{ |line| line != "" }.size