**app.use()** handles all the middleware functions.
What is middleware?
Middlewares are the functions that work like a door between two all the routes.

For instance:

***app.use((req, res, next) => {
console.log("middleware ran");
next();
});

app.get("/", (req, res) => {
console.log("Home route");
});***
When you visit / route in your console the two message will be printed. The first message will be from middleware function. If there is no next() function passed then only middleware function runs and other routes are blocked.

Windows solution: Replace spawn with node-cross-spawn. For instance like this at the beginning of your app.js:

***(function() {
var childProcess = require("child_process");
childProcess.spawn = require('cross-spawn');
})(); ***

Set a crontab for this

***#crontab -e
@reboot /home/user/test.sh***
after every startup it will run the test script.

From documentation:

***{
"scripts": {
"build": "cross-env NODE_ENV=production OTHERFLAG=myValue webpack --config build/webpack.config.js"
}
}***
Notice that if you want to set multiple global vars, you just state them in succession, followed by your command to be executed.

Ultimately, the command that is executed (using spawn) is:

***webpack --config build/webpack.config.js***
The NODE_ENV environment variable will be set by cross-env

This is just extra information, but if you really want the string in a header file, try something like:

***class foo
{
public:
static const std::string& RECTANGLE(void)
{
static const std::string str = "rectangle";

return str;
}
};***

You either want a Table-Valued function or insert your EXEC into a temporary table:

***INSERT INTO #tab EXEC MyProc***

Try this...

***update [table_name] set [field_name] =
replace([field_name],'[string_to_find]','[string_to_replace]');***

In Java 8 you can do this

***int[] ints = {1,2,3};
List list = Arrays.stream(ints).boxed().collect(Collectors.toList());***

I feel it would be helpful for someone who is looking for passing the array in a query string to a servlet. I tested below query string and was able to get the array values using req.getgetParameterValues(); method. Below is the query string I passed through browser.

*** http://localhost:8080/ServletsTutorials/*.html?
myname=abc&initial=xyz&checkbox=a&checkbox=b***

As optional chaining proposal reached stage 4 and is getting wider support, there is a very elegant way to do this

***if(image_array?.length){

// image_array is defined and has at least one element

}***

If you're using MySQL, you can use

***SELECT GREATEST(col1, col2 ...) FROM table***

IF you want an identity column in the new table created with select into then it can be done as below.

***SELECT
ID = IDENTITY(INT, 1, 1),
name
INTO table2
FROM table1***