第一次发现javascript中replace() 方法如果直接用str.replace("-","!") 只会替换第一个匹配的字符.
replace()
Thereplace()methodreturnsthestringthatresultswhenyoureplacetextmatchingitsfirstargument
(aregularexpression)withthetextofthesecondargument(astring).
Iftheg(global)flagisnotsetintheregularexpressiondeclaration,thismethodreplacesonlythefirst
occurrenceofthepattern.Forexample,

vars="Hello.Regexpsarefun.";s=s.replace(/\./,"!");//replacefirstperiodwithanexclamationpointalert(s);
producesthestring“Hello!Regexpsarefun.”Includingthegflagwillcausetheinterpreterto
performaglobalreplace,findingandreplacingeverymatchingsubstring.Forexample,

vars="Hello.Regexpsarefun.";s=s.replace(/\./g,"!");//replaceallperiodswithexclamationpointsalert(s);
yieldsthisresult:“Hello!Regexpsarefun!”
我刚刚用它作了如下操作
把 |aaa|bbb|切换成,aaa,bbb,
replace(/\|/g, ",") 参数里边的/是用来转义的,\| 是能代表"|"么?