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10-regular-expressions/13-regexp-multiline-mode/article.md

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+# Multiline mode, flag "m"
+
+The multiline mode is enabled by the flag `pattern:/.../m`.
+
+[cut]
+
+It only affects the behavior of `pattern:^` and `pattern:$`.
+
+In the multiline mode they match not only at the beginning and end of the string, but also at start/end of line.
+
+## Line start ^
+
+In the example below the text has multiple lines. The pattern `pattern:/^\d+/gm` takes a number from the beginning of each one:
+
+```js run
+let str = `1st place: Winnie
+2nd place: Piglet
+33rd place: Eeyore`;
+
+*!*
+alert( str.match(/^\d+/gm) ); // 1, 2, 33
+*/!*
+```
+
+Without the flag  `pattern:/.../m` only the first number is matched:
+
+
+```js run
+let str = `1st place: Winnie
+2nd place: Piglet
+33rd place: Eeyore`;
+
+*!*
+alert( str.match(/^\d+/g) ); // 1
+*/!*
+```
+
+That's because by default a caret `pattern:^` only matches at the beginning of the text, and in the multiline mode -- at the start of a line.
+
+The regular expression engine moves along the text and looks for a string start `pattern:^`, when finds -- continues to match the rest of the pattern `pattern:\d+`.
+
+## Line end $
+
+The dollar sign `pattern:$` behaves similarly.
+
+The regular expression `pattern:\w+$` finds the last word in every line
+
+```js run
+let str = `1st place: Winnie
+2nd place: Piglet
+33rd place: Eeyore`;
+
+alert( str.match(/\w+$/gim) ); // Winnie,Piglet,Eeyore
+```
+
+Without the `pattern:/.../m` flag the dollar `pattern:$` would only match the end of the whole string, so only the very last word would be found.
+
+## Anchors ^$ versus \n
+
+To find a newline, we can use not only `pattern:^` and `pattern:$`, but also the newline character `\n`.
+
+The first difference is that unlike anchors, the character `\n` "consumes" the newline character and adds it to the result.
+
+For instance, here we use it instead of `pattern:$`:
+
+```js run
+let str = `1st place: Winnie
+2nd place: Piglet
+33rd place: Eeyore`;
+
+alert( str.match(/\w+\n/gim) ); // Winnie\n,Piglet\n
+```
+
+Here every match is a word plus a newline character.
+
+And one more difference -- the newline `\n` does not match at the string end. That's why `Eeyore` is not found in the example above.
+
+So, anchors are usually better, they are closer to what we want to get.