javascript复习4：RegExpvar strIs this all there isvar patt1/is(? all)/document.write(str.matc
javascript复习4：RegExp
var str="Is this all there is";var patt1=/is(?= all)/;document.write(str.match(patt1));
javascript复习4：RegExp
var str="Is this all there is";var patt1=/is(?= all)/;document.write(str.match(patt1));