How do you use the Immediate Window in Visual Studio

Question

The Immediate Window is an immensely useful tool for debugging applications  It can be used to execute code statements that are valid in the context of a break point and inspect values  I also use it to type code snippets to learn language features   How do you use the Immediate Window

User · Answer

The Immediate window is used to debug and evaluate expressions, execute statements, print variable values, and so forth. It allows you to enter expressions to be evaluated or executed by the development language during debugging.

To display Immediate Window, choose Debug >Windows >Immediate or press Ctrl-Alt-I

Here is an example with Immediate Window:

int Sum(int x, int y) { return (x + y);}
void main(){
int a, b, c;
a = 5;
b = 7;
c = Sum(a, b);
char temp = getchar();}

add breakpoint

call commands

https://msdn.microsoft.com/en-us/library/f177hahy.aspx

User · Answer

One nice feature of the Immediate Window in Visual Studio is its ability to evaluate the return value of a method particularly if it is called by your client code but it is not part of a variable assignment  In Debug mode  as mentioned  you can interact with variables and execute expressions in memory which plays an important role in being able to do this   For example  if you had a static method that returns the sum of two numbers such as   private static int GetSum int a  int b        return a   b      Then in the Immediate Window you can type the following     GetSum 2  4  6   As you can seen  this works really well for static methods   However  if the method is non-static then you need to interact with a reference to the object the method belongs to   For example  let   s say this is what your class looks like    private class Foo       public string GetMessage                 return  hello             If the object already exists in memory and it   s in scope  then you can call it in the Immediate Window as long as it has been instantiated before your current breakpoint  or  at least  before wherever the code is paused in debug mode      foo GetMessage       object    foo    already exists  hello    In addition  if you want to interact and test the method directly without relying on an existing instance in memory  then you can instantiate your own instance in the Immediate Window     Foo foo   new Foo       new instance of    Foo     temp Program Foo    foo GetMessage    hello    You can take it a step further and temporarily assign the method s results to variables if you want to do further evaluations  calculations  etc      string msg   foo GetMessage     hello    msg     there    hello there     Furthermore  if you don   t even want to declare a variable name for a new object and just want to run one of its methods functions then do this      new Foo   GetMessage    hello     A very common way to see the value of a method is to select the method name of a class and do a    Add Watch    so that you can see its current value in the Watch window   However  once again  the object needs to be instantiated and in scope for a valid value to be displayed   This is much less powerful and more restrictive than using the Immediate Window   Along with inspecting methods  you can do simple math equations     5   6 30   or compare values     5  6 false   6  6 true   The question mark       is unnecessary if you are in directly in the Immediate Window but it is included here for clarity  to distinguish between the typed in expressions versus the results    However  if you are in the Command Window and need to do some quick stuff in the Immediate Window then precede your statements with     and off you go   Intellisense works in the Immediate Window  but it sometimes can be a bit inconsistent  In my experience  it seems to be only available in Debug mode  but not in design  non-debug mode   Unfortunately  another drawback of the Immediate Window is that it does not support loops

User · Answer

Use the Immediate Window to Execute Commands  The Immediate Window can also be used to execute commands  Just type a  gt  followed by the command     For example  gt shell cmd will start a command shell  this can be useful to check what environment variables were passed to Visual Studio  for example    gt cls will clear the screen   Here is a list of commands that are so commonly used that they have their own aliases  https   msdn microsoft com en-us library c3a0kd3x aspx

[visual-studio] How do you use the Immediate Window in Visual Studio?

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