Javascript（节点）正则表达式似乎与字符串开头不匹配

Question

im struggling with regular expressions in Javascript, they don't seem to start at the beginning of the string. In a simple example bellow I want to get the file name and then everything after the first colon

 //string
 file.text:16:  lots of random text here with goes on for ages

 //regex
 (.?)[:](.*)

 // group 1 returns 't'

Answer 1

/^([^:]+):(.*)/.exec('file.text:16:  lots of random text here with goes on for ages')

给....

["file.text:16:  lots of random text here with goes on for ages", "file.text", "16:  lots of random text here with goes on for ages"]

Answer 2

Try this regex:

/^([^:]+)[:](.*)/

Explaination:

^       #Start of string
(       #Start of capturing class #1
  [^:]    #Any character other than :
  +       #One or more of the previous character class
)       #End of capturing class #1
[:]     #One :
(.*)    #Any number of characters other than newline

The ? operator captures zero or one of the previous symbol only.

You could also use string operations instead:

str = "file.text:16:";
var n = str.indexOf(":");
var fileName = str.substr(0, n);
var everythingElse = str.substr(n);

Answer 3

The ? operator returns 0 or 1 matches. You want the * operator, and you should select everything that isn't a : in the first set

  ([^:]*)[:](.*)

Answer 4

Non-regexy answer:

var a = s.split(":");

Then join a[1] and remaining elements.

Or just get the index of the first semicolon and create two strings using that.