主页
JS 参考手册
JavaScript 正则表达式否定后行断言 (?<!y)x
tryjsref_regexp_negative_lookbehind
运行 ❯
×
更改方向
保存代码
更改主题
<!DOCTYPE html> <html> <body> <h1>Regular Expressions</h1> <h2>Negative Lookbehind Assertion</h2> <p>Match "FreeW3C" only if "FreeW3C" is NOT preceded by "Hello ".</p> <p id="demo"></p> <script> let text = "Hello FreeW3C"; let pattern = /(?<!Hello )FreeW3C/; let result = pattern.test(text); document.getElementById("demo").innerHTML = result; </script> </body> </html>