Calling Functions in VS .NET
Calling Functions Create Bar Code In .NET Framework Using Barcode maker for ASP.NET Control to generate, create bar code image in ASP.NET applications. How do you call a function The same way you call your dog! Just say its name: Generate Denso QR Bar Code In C#.NET Using Barcode generation for .NET framework Control to generate, create QR image in .NET framework applications. 7: Divide and Conquer: Structured Programming
Painting Denso QR Bar Code In Visual Studio .NET Using Barcode creation for .NET Control to generate, create QR image in Visual Studio .NET applications. <body> <p>I ll roll two dice; let s see what we get!</p> <% Dim FirstRoll, SecondRoll As Integer FirstRoll = RollDie SecondRoll = RollDie %> First roll: <%=FirstRoll%> Second roll: <%=SecondRoll%> </body> </html> This code creates two integer variables: FirstRoll and SecondRoll Then, the function is called by invoking its name: RollDie The function s body is executed: Function RollDie As Integer Dim Roll As Integer Randomize Roll = Int(Rnd * 6) + 1 Return Roll End Function The function creates a variable called Roll and assigns it the value from the random number formula Now Roll has a value between 1 and 6 The last line of the function body indicates what value the function will return In this case, the function returns the number that s in the Roll variable The value returned must match the type at the end of the Function line in this case, As Integer If the value doesn t match the type, you ll receive an error When the function is done, execution returns to the place where the function was called The value returned from the RollDie function is assigned to the variable FirstRoll: FirstRoll = RollDie To clarify, the preceding line does two things: It calls the RollDie function created in the <script> section at the top of the page All the lines in the body of the function are executed After the function is called, the value returned effectively replaces the name of the function in the code So in this case, the function generates a random number between 1 and 6, and that number comes back and gets assigned to the FirstRoll variable Make QR In VB.NET Using Barcode creator for .NET Control to generate, create QR Code image in VS .NET applications. Part III: Speaking the Language
Make Bar Code In VS .NET Using Barcode generation for ASP.NET Control to generate, create barcode image in ASP.NET applications. The RollDie function is called again on the next line to put another random number in the SecondRoll variable: SecondRoll = RollDie Finally, the page displays both values: First roll: <%=FirstRoll%> Second roll: <%=SecondRoll%> As you try this example, click the Refresh button several times You get a different roll each time The results look something like this: I ll roll two dice; let s see what we get! First roll: 2 Second roll: 4 You can create as many functions as you like Each can contain any number of commands, and you can call these functions from anywhere in your program as many times as you like You can even call functions from within other functions Barcode Creator In Visual Studio .NET Using Barcode maker for ASP.NET Control to generate, create bar code image in ASP.NET applications. Opening Arguments
Creating UPCA In Visual Studio .NET Using Barcode creation for VS .NET Control to generate, create GS1 - 12 image in Visual Studio .NET applications. In some cases, you need to give a function some information so that it can do its job You pass information to a function by using arguments To demonstrate this concept, I go back to the drawing board for generating random numbers The example in the preceding section uses a RollDie function You could create a FlipCoin function and a DrawCard function, each returning random numbers within different ranges Or you could create a more generalized random number function as shown in Listing 7-2: DataMatrix Creation In C#.NET Using Barcode generation for .NET Control to generate, create ECC200 image in Visual Studio .NET applications. Listing 7-2: Read ANSI/AIM Code 128 In .NET Framework Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET framework applications. Generalizing the Function
Decoding EAN13 In VS .NET Using Barcode scanner for .NET framework Control to read, scan read, scan image in .NET applications. <%@ Page Explicit= True Language= VB Debug= True %> <html> <script runat= server > Function RandNum(Limit As Integer) As Integer Dim Num As Integer Randomize Num = Int(Rnd * Limit) + 1 Return(Num) End Function Encode Code-39 In C# Using Barcode maker for Visual Studio .NET Control to generate, create Code 39 image in VS .NET applications. 7: Divide and Conquer: Structured Programming
USS Code 128 Generation In Java Using Barcode maker for Java Control to generate, create Code 128 image in Java applications. </script> <body> <p>And now, the multi-talented RandNum function!</p> A Die Roll: <%=RandNum(6)%><br> A Card Draw: <%=RandNum(13)%><br> A Coin Flip: <%=RandNum(2)%><br> </body> </html> Again, the Function and End Function lines surround the indented body of the function The name of the function is RandNum But this time, parentheses follow the function name and something that looks like a variable declaration (without the Dim) appears inside What s going on there Inside the parentheses you create a variable declaration of sorts so that you can identify the information sent as an argument to the function with a name and a data type It looks like a normal variable declaration without the Dim You only use Dim when you create stand-alone variables With arguments when you call this RandNum function, you use the integer variable Limit to refer to the information that you pass into this function as an argument The As Integer clause that follows the parentheses looks a little out of place now, but it s the same As Integer clause that appears immediately after a function name when there are no parentheses (like the RollDie function created in the preceding section) It indicates that this function will return an integer value All the rest of the function looks the same as the earlier example (in Listing 7-1) except for one thing I use the Limit variable in the random number formula to indicate the highest random number generated So, if the programmer passes in a 5, the function generates a random number between 1 and 5 If the programmer passes in 500, the function returns a random number between 1 and 500 The body of the function isn t executed until the function is called That happens in the body of the page In this example, I don t bother with creating variables, calling the function, assigning the returned value to the variable, and then displaying the variable, as I do in Listing 7-1 Instead, I just call the function and immediately display whatever it sends back: A A A Die Roll: <%=RandNum(6)%><br> Card Draw: <%=RandNum(13)%><br> Coin Flip: <%=RandNum(2)%><br> ANSI/AIM Code 39 Scanner In .NET Framework Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications. Bar Code Generator In .NET Using Barcode generator for .NET Control to generate, create barcode image in VS .NET applications. Bar Code Drawer In Java Using Barcode encoder for Java Control to generate, create bar code image in Java applications. Drawing EAN13 In Visual C# Using Barcode encoder for VS .NET Control to generate, create European Article Number 13 image in VS .NET applications. Encoding Barcode In .NET Using Barcode maker for .NET framework Control to generate, create bar code image in Visual Studio .NET applications. |
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