Remove a string from the beginning of a string

Question

I have a string that looks like this    str    bla string bla bla bla     How can I remove the first bla   but only if it s found at the beginning of the string   With str replace    it removes all bla  s

User · Answer

This will remove first match wherever it is found i e   start or middle or end    str   substr  str  0  strpos  str   prefix   substr  str  strpos  str   prefix  strlen  prefix

User · Answer

Here s an even faster approach      strpos is faster than an unnecessary substr   and is built just for that  if  strpos  str   prefix      0   str   substr  str  strlen  prefix

User · Answer

I think substr replace does what you want  where you can limit your replace to part of your string  http   nl3 php net manual en function substr-replace php  This will enable you to only look at the beginning of the string    You could use the count parameter of str replace   http   nl3 php net manual en function str-replace php    this will allow you to limit the number of replacements  starting from the left  but it will not enforce it to be at the beginning

User · Answer

str replace   mixed  search   mixed  replace   mixed  subject    int  amp  count      now does what you want    str    bla string bla bla bla   str replace  bla       str 1

User · Answer

Here    array   explode       string   if  array 0      bla   array shift  array    string   implode       array

User · Answer

Nice speed  but this is hard-coded to depend on the needle ending with    Is there a general version      toddmo Jun 29 at 23 26    A general version    parts   explode  start   full  2   if   parts 0                 end    parts 1     else        fail   true      Some benchmarks    lt  php   iters   100000   start     aaaaaaa bbbbbbbbbb    full     aaaaaaa bbbbbbbbbb cccccccccc dddddddddd eeeeeeeeee    end         fail   false    t0   microtime true   for   i   0   i  lt   iters   i          if  strpos  full   start      0             end   substr  full  strlen  start          else            fail   true           t   microtime true  -  t0  printf   16s    f s n    strpos strlen    t     t0   microtime true   for   i   0   i  lt   iters   i           parts   explode  start   full  2       if   parts 0                     end    parts 1         else            fail   true           t   microtime true  -  t0  printf   16s    f s n    explode    t     On my quite old home PC     php bench php   Outputs      strpos strlen   0 158388 s          explode   0 126772 s

User · Answer

function remove prefix  text   prefix        if 0     strpos  text   prefix            text   substr  text  strlen  prefix           return  text

User · Answer

Plain form  without regex    prefix    bla     str    bla string bla bla bla    if  substr  str  0  strlen  prefix       prefix         str   substr  str  strlen  prefix         Takes  0 0369 ms  0 000 036 954 seconds   And with    prefix    bla     str    bla string bla bla bla    str   preg replace        preg quote  prefix                   str     Takes  0 1749 ms  0 000 174 999 seconds  the 1st run  compiling   and 0 0510 ms  0 000 051 021 seconds  after   Profiled on my server  obviously

User · Answer

lt  php  str    bla string bla bla bla   echo preg replace   bla          str  1      gt

User · Answer

Remove www  from beginning of string  this is the easiest way  ltrim    a  www google com   echo ltrim  a   www

User · Answer

You can use regular expressions with the caret symbol     which anchors the match to the beginning of the string    str   preg replace    bla          str

[php] Remove a string from the beginning of a string

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