MySQL: @variable vs. variable. Whats the difference? In MySQL, @variable indicates a user-defined variable You can define your own SET @a = 'test'; SELECT @a; Outside of stored programs, a variable, without @, is a system variable, which you cannot define yourself The scope of this variable is the entire session
++someVariable vs. someVariable++ in JavaScript - Stack Overflow ++x (pre-increment) means "increment the variable; the value of the expression is the final value" x++ (post-increment) means "remember the original value, then increment the variable; the value of the expression is the original value" Now when used as a standalone statement, they mean the same thing: x++; ++x;
What does the @ symbol before a variable name mean in C#? Firstly, it allows you to use a reserved keyword as a variable like this: int @int = 15; The second option lets you specify a string without having to escape any characters For instance the '\' character is an escape character so typically you would need to do this: var myString = "c:\\myfolder\\myfile txt" alternatively you can do this:
Defining and using a variable in batch file - Stack Overflow Consider also using SETX - it will set variable on user or machine (available for all users) level though the variable will be usable with the next opening of the cmd exe ,so often it can be used together with SET:
Difference between %variable% and !variable! in batch file The value of the !_var! variable is evaluated as late as possible while the %_var% variable works just as before Delayed Expansion will cause variables within a batch file to be expanded at execution time rather than at parse time This will allow you to always read the current value of the variable
How do I use variables in Oracle SQL Developer? - Stack Overflow SQL> variable v_emp_id number; SQL> select 1234 into :v_emp_id from dual; 1234 ----- 1234 SQL> select * 2 from emp 3 where empno = :v_emp_id; no rows selected In SQL Developer, if you run a statement that has any number of bind variables (prefixed with a colon), you'll be prompted to enter values
JavaScript OR (||) variable assignment explanation - Stack Overflow In summary, this technique is taking advantage of a feature of how the language is compiled That is, JavaScript "short-circuits" the evaluation of Boolean operators and will return the value associated with either the first non-false variable value or whatever the last variable contains
Passing additional variables from command line to make Every environment variable that make sees when it starts up is transformed into a make variable with the same name and value However, an explicit assignment in the makefile, or with a command argument, overrides the environment So you can do (from bash): FOOBAR=1 make resulting in a variable FOOBAR in your Makefile