javascript string.replace 在 node.js express 服务器中不起作用
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string.replace not working in node.js express server
提问by Damodaran
I need to read a file and replace some texts in that file with dynamic content.when i tried string.replace it is not working for the data that i read from the file.But for the string it is working.I am using node.js and express.
我需要读取一个文件并用动态内容替换该文件中的一些文本。当我尝试 string.replace 时，它不适用于我从文件中读取的数据。但是对于它正在工作的字符串。我正在使用节点。 js和快递。
fs.readFile('test.html', function read(err, data) {
if (err) {
console.log(err);
}
else {
var msg = data.toString();
msg.replace("%name%", "myname");
msg.replace(/%email%/gi, '[email protected]');
temp = "Hello %NAME%, would you like some %DRINK%?";
temp = temp.replace(/%NAME%/gi,"Myname");
temp = temp.replace("%DRINK%","tea");
console.log("temp: "+temp);
console.log("msg: "+msg);
}
});
Output:
输出：
temp: Hello Myname, would you like some tea?
msg: Hello %NAME%, would you like some %DRINK%?
回答by Asad Saeeduddin
msg = msg.replace(/%name%/gi, "myname");
You're passing a string instead of a regex to the first replace, and it doesn't match because the case is different. Even if it did match, you're not reassigning this modified value to msg. This is strange, because you're doing everything correctly for tmp.
您将字符串而不是正则表达式传递给第一个替换，它不匹配，因为大小写不同。即使它确实匹配，您也不会将此修改后的值重新分配给msg。这很奇怪，因为您对tmp.
回答by Muthu Kumaran
You need to assign variable for .replace()which returns the string. In your case, you need to do like, msg = msg.replace("%name%", "myname");
您需要为其分配.replace()返回字符串的变量。在你的情况下，你需要这样做，msg = msg.replace("%name%", "myname");
Code:
代码：
fs.readFile('test.html', function read(err, data) {
if (err) {
console.log(err);
}
else {
var msg = data.toString();
msg = msg.replace("%name%", "myname");
msg = msg.replace(/%email%/gi, '[email protected]');
temp = "Hello %NAME%, would you like some %DRINK%?";
temp = temp.replace(/%NAME%/gi,"Myname");
temp = temp.replace("%DRINK%","tea");
console.log("temp: "+temp);
console.log("msg: "+msg);
}
});
回答by alex
replace()returns a new string with the replaced substrings, so you must assign that to a variable in order to access it. It does not mutate the original string.
replace()返回一个带有替换子字符串的新字符串，因此您必须将其分配给一个变量才能访问它。它不会改变原始字符串。
You would want to write the transformed string back to your file.
您可能希望将转换后的字符串写回您的文件。
