现场演示：我的 HTML 文档

xxxxxxxxxx
 
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>JavaScript Replace Character in a String</title>
<script>
    function strReplace(){
        var myStr = 'quick_brown_fox';
        var newStr = myStr.replace(/_/g, "-");
        
        // Insert modified string in paragraph
        document.getElementById("myText").innerHTML = newStr;
    }
</script>
</head>
<body>
    <p id="myText">quick_brown_fox</p>
    <button type="button" onclick="strReplace();">Replace</button>
</body>
</html>