c# - How to get the line count in a string using .NET (with any line break) -

i need count number of lines in string. line break can character can present in string (cr, lf or crlf).

so possible new line chars: * \n * \r * \r\n 

for example, following input:

this [\n] string [\r] has 4 [\r\n] lines 

the method should return 4 lines. know built in function, or implemented it?

static int getlinecount(string input) {    // provide implementation method?    // want avoid string.split since performs bad } 

note: performance important me, because read large strings.

thanks in advance.

int count = 0; int len = input.length; for(int = 0; != len; ++i)   switch(input[i])   {     case '\r':       ++count;       if (i + 1 != len && input[i + 1] == '\n')         ++i;       break;     case '\n':     // uncomment below include other line break sequences     // case '\u000a':     // case '\v':     // case '\f':     // case '\u0085':     // case '\u2028':     // case '\u2029':       ++count;       break;   } 

simply scan through, counting line-breaks, , in case of \r test if next character \n , skip if is.

performance important me, because read large strings.

if @ possible then, avoid reading large strings @ all. e.g. if come streams pretty easy directly on stream there no more one-character read-ahead ever needed.

here's variant doesn't count newlines @ end of string:

int count = 1; int len = input.length - 1; for(int = 0; < len; ++i)   switch(input[i])   {     case '\r':     if (input[i + 1] == '\n')     {       if (++i >= len)       {         break;       }     }     goto case '\n';         case '\n':         // uncomment below include other line break sequences         // case '\u000a':         // case '\v':         // case '\f':         // case '\u0085':         // case '\u2028':         // case '\u2029':           ++count;           break;         } 

this therefore considers "", "a line", "a line\n" , "a line\r\n" each 1 line only, , on.