var str="javascript coffeescript vbscript javacode"
var re1=/\b\w+script\b/g
var re2=/(?=java)\b\w+script\b/g
var re3=/(?!java)\b\w+script\b/g
console.log( str.match(re1))
console.log( str.match(re2))
console.log( str.match(re3))
Ответ:
[ 'javascript', 'coffeescript', 'vbscript' ]
[ 'javascript' ]
[ 'coffeescript', 'vbscript' ]
JavaScript test | #JavaScript