Is there a difference between s g and s g

Question

When we have a string that contains space characters   var str      A B  C   D EF      and we want to remove the spaces from the string  we want this   ABCDEF     Both this   str replace   s g        and this   str replace   s  g        will return the correct result   Does this mean that the   is superfluous in this situation  Is there a difference between those two regular expressions in this situation  as in  could they in any way produce different results      Update  Performance comparison -   s  g is faster  See here  http   jsperf com s-vs-s

User · Answer

means  one or more characters  and without the plus it means  one character   In your case both result in the same output

User · Answer

In a match situation the first would return one match per whitespace  when the second would return a match for each group of whitespaces   The result is the same because you re replacing it with an empty string  If you replace it with  x  for instance  the results would differ   str replace   s g      will return  xxAxBxxCxxxDxEF    while str replace   s  g      will return  xAxBxCxDxEF    because  s matches each whitespace  replacing each one with  x   and  s  matches groups of whitespaces  replacing multiple sequential whitespaces with a single  x

User · Answer

s means  one space   and  s  means  one or more spaces    But  because you re using the  g flag  replace all occurrences  and replacing with the empty string  your two expressions have the same effect

User · Answer

In the first regex  each space character is being replaced  character by character  with the empty string   In the second regex  each contiguous string of space characters is being replaced with the empty string because of the     However  just like how 0 multiplied by anything else is 0  it seems as if both methods strip spaces in exactly the same way   If you change the replacement string to      the difference becomes much clearer   var str      A B  C   D EF    console log str replace   s g               A B  C   D EF  console log str replace   s  g             A B C D EF

[javascript] Is there a difference between /\s/g and /\s+/g?

Examples related to javascript

Examples related to regex