javascript 循环 nodejs 中的 setInterval
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9717884/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
setInterval in loop nodejs
提问by Jed
I know that there are other questions just like this but my code just doesnt seems to work. Could you have a look at my code and tell me where i am wrong.
我知道还有其他类似的问题，但我的代码似乎不起作用。你能不能看看我的代码，告诉我哪里错了。
var mysql = require('mysql');
var client = mysql.createClient({
user: 'jed',
password: 'jed8703',
host: 'localhost',
database: 'jedtest'
});
//var query = client.query(
// 'INSERT INTO testtable '+
// 'SET testid = ?, name = ?, value = ?',
// [1, 'test', 'test']
//);
client.query(
'SELECT * FROM testtable',
function selectCb(err, results, fields) {
if (err) {
throw err;
}
console.log(results[0].Name);
for(var i in results)
{
(function(y)
{
setInterval(function() {
console.log(results[y].Name + 'value:' + results[y].Value );
}, 5000 );
})
}
}
);
client.end();
回答by Rob W
Don't forget to invoke the function:
不要忘记调用函数：
(function(y)
{
setInterval(function() {
console.log(results[y].Name + 'value:' + results[y].Value );
}, 5000 );
})(i); // <------- Added (i);
Note that your delay may not behave as expected. Currently, you're executing all methods after 5 seconds. Create a queue if you want to have a delay of 5 seconds between each call.
请注意，您的延迟可能不会按预期进行。目前，您将在 5 秒后执行所有方法。如果您希望每次调用之间有 5 秒的延迟，请创建一个队列。
回答by Sarfraz
You are not fullfilling yvariable, try replacing:
您没有填充y变量，请尝试替换：
(function(y)
{
setInterval(function() {
console.log(results[y].Name + 'value:' + results[y].Value );
}, 5000 );
})
With:
和：
(function(y)
{
setInterval(function() {
console.log(results[y].Name + 'value:' + results[y].Value );
}, 5000 );
})(i); // <------------------
