There are two types of formats that YAML supports for strings: block scalar and flow scalar formats. (Scalars are what YAML calls basic values like numbers or strings, as opposed to complex types like arrays or objects.) Block scalars have more control over how they are interpreted, whereas flow scalars have more limited escaping support.
Block Scalars
A block scalar header has three parts:
Block Style Indicator: The block style indicates
how newlines inside the block should behave.
If you would like them to be kept as newlines, use the literal
style, indicated by a pipe (|).
If instead you want them to be replaced by spaces, use the folded
style, indicated by a right angle bracket (>).
(To get a newline using the folded style, leave a blank line by putting two newlines in.
Lines with extra indentation are also not folded.)
Block Chomping Indicator:
The chomping indicator controls what should happen with newlines
at the end of the string.
The default, clip, puts a single newline at the end of the string.
To remove all newlines, strip them by putting a minus sign (-)
after the style indicator.
Both clip and strip ignore how many newlines are actually at the end of the block;
to keep them all put a plus sign (+) after the style indicator.
Indentation Indicator: Ordinarily, the number of spaces you're using to indent a block will be automatically guessed from its first line. You may need a block indentation indicator if the first line of the block starts with extra spaces. In this case, simply put the number of spaces used for indentation (between 1 and 9) at the end of the header.
Demo
example: |>-+\n ··Several lines of text,\n ··with some "quotes" of various 'types',\n ··and also a blank line:\n ··\n ··and some text with\n ··extra indentation\n ··on the next line,\n ··plus another line at the end.\n ··\n ··\n
Several lines of text,\n with some "quotes" of various 'types',\n and also a blank line:\n \n and some text with\n extra indentation\n on the next line,\n plus another line at the end.\n \n \n
Flow Scalars
Single-quoted
example: 'Several lines of text,\n ··containing ''single quotes''. Escapes (like \n) don''t do anything.\n ··\n ··Newlines can be added by leaving a blank line.\n ····Leading whitespace on lines is ignored.'\n
Several lines of text, containing 'single quotes'. Escapes (like \n) don't do anything.\n
Newlines can be added by leaving a blank line. Leading whitespace on lines is ignored.Double-quoted
example: "Several lines of text,\n ··containing \"double quotes\". Escapes (like \\n) work.\nIn addition,\n ··newlines can be esc\\n ··aped to prevent them from being converted to a space.\n ··\n ··Newlines can also be added by leaving a blank line.\n ····Leading whitespace on lines is ignored."\n
Several lines of text, containing "double quotes". Escapes (like \n) work.\n In addition, newlines can be escaped to prevent them from being converted to a space.\n Newlines can also be added by leaving a blank line. Leading whitespace on lines is ignored.\n
Plain
example: Several lines of text,\n ··with some "quotes" of various 'types'.\n ··Escapes (like \n) don't do anything.\n ··\n ··Newlines can be added by leaving a blank line.\n ····Additional leading whitespace is ignored.\n
Several lines of text, with some "quotes" of various 'types'. Escapes (like \n) don't do anything.\n
Newlines can be added by leaving a blank line. Additional leading whitespace is ignored.Note:
Plain flow scalars are picky about the : and # characters.
They can be in the string,
but : cannot appear before a space or newline,
and # cannot appear after a space or newline;
doing this will cause a syntax error.
If you need to use these characters you are probably better off
using one of the quoted styles instead.