JQuery Replace replaces all

Days to write a program encountered the need to replace the function, but at the beginning of the jquery replace, found only replaced by the first one. In the end, I had to use regular expressions to
For example, below

Re = new RegExp ("{thisclassid}", "G"); str = str.replace (Re, "123");

It means to replace all the "{THISCLASSID}" in Str with 123.
RegExp ("{thisclassid}", "G"); The first parameter is the one you want to replace the second argument "G" is the meaning of the match, or "T", which matches the first one.

JQuery Replace replaces all