How-to articles, tricks, and solutions about VARIABLES
"No X11 DISPLAY variable" - what does it mean?
"No X11 DISPLAY variable" is an error message that you might see when trying to run a Java program that uses the X Window System to display a graphical user interface (GUI).
accessing a variable from another class
To access a variable from another class in Java, you can use the following steps:
Best way to test for a variable's existence in PHP; isset() is clearly broken
In PHP, the isset() function is used to check if a variable has been set, meaning that it has been declared and is not equal to NULL.
Can't access global variable inside function
In PHP, if you want to access a global variable inside a function, you need to use the "global" keyword.
Changing a global variable from inside a function PHP
In PHP, global variables can be accessed and modified from within functions using the global keyword.
How can I print variable and string on same line in Python?
You can use the print() function in Python and use the + operator to concatenate a string and a variable.
How do I check if a variable exists?
In Python, you can check if a variable exists by using the globals() or locals() function to check if the variable is in the global or local namespace, respectively.
How do I put a variable’s value inside a string (interpolate it into the string)?
In Python, you can use the format() method or f-strings (available in Python 3.6 and above) to interpolate a variable's value into a string.
How do you know a variable type in java?
You can use the instanceof operator to determine the type of a variable in Java.