相同的正则表达式,不同的结果;
爪哇
String regex = "Windows(?=95|98|NT|2000)";
String str = "Windows2000";
Pattern p = Pattern.compile(regex);
Matcher m = p.matcher(str);
System.out.println(m.matches()); // print false
Run Code Online (Sandbox Code Playgroud)
JavaScript
var value = "Windows2000";
var reg = /Windows(?=95|98|NT|2000)/;
console.info(reg.test(value)); // print trueRun Code Online (Sandbox Code Playgroud)
我不明白为什么会这样?