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leitor de qr code para celular java download Variables, Operators, and Expressions in Java
CHAPTER 2 Variables, Operators, and Expressions Quick Response Code Drawer In Java Using Barcode drawer for Java Control to generate, create QR Code ISO/IEC18004 image in Java applications. Recognizing QR In Java Using Barcode scanner for Java Control to read, scan read, scan image in Java applications. The next line displays the sales tax on the screen by calling the alert() function As you recall from 1, the alert() function requires you to place the message that you want displayed between the parentheses In this example, we use the plus operator (+) to place the value of the SalesTax variable at the end of the text statement Sales tax is $ (see Figure 23) Barcode Maker In Java Using Barcode printer for Java Control to generate, create bar code image in Java applications. Bar Code Reader In Java Using Barcode scanner for Java Control to read, scan read, scan image in Java applications. Strings
QR Code 2d Barcode Drawer In Visual C#.NET Using Barcode maker for .NET Control to generate, create QR Code JIS X 0510 image in .NET applications. QR Generation In .NET Using Barcode encoder for ASP.NET Control to generate, create QR image in ASP.NET applications. Although our examples use numbers to show you how to initialize and assign values to a variable, you can also initialize and assign words and punctuation to a variable To do this, you write the declaration statement and assignment statement the same way shown in previous examples, except you enclose words and punctuation within quotation marks T IP JavaScript allows both single and double quotation marks to be used to designate a string It is always better to use single quotation marks, though, because the double quotation marks might interfere with double quotation marks used in the HTML page Using single quotation marks avoids any potential interference Here is a new example The rst line declares a variable called ProductName and initializes it with the text Soda The second line assigns Water to the ProductName variable: Encode QRCode In .NET Using Barcode generation for .NET framework Control to generate, create QR Code ISO/IEC18004 image in .NET framework applications. Paint QR Code 2d Barcode In VB.NET Using Barcode encoder for Visual Studio .NET Control to generate, create QR Code image in .NET applications. var ProductName = 'Soda' ProductName = 'Water' UCC128 Generator In Java Using Barcode encoder for Java Control to generate, create EAN 128 image in Java applications. Code 128 Printer In Java Using Barcode creator for Java Control to generate, create Code 128 Code Set B image in Java applications. Figure 23 The alert() function displays the alert dialog box that displays the sales tax that is calculated by the JavaScript Generating UCC  12 In Java Using Barcode generation for Java Control to generate, create GTIN  12 image in Java applications. EAN / UCC  13 Creation In Java Using Barcode generator for Java Control to generate, create EAN / UCC  13 image in Java applications. JavaScript Demysti ed
Painting 2/5 Interleaved In Java Using Barcode generator for Java Control to generate, create Uniform Symbology Specification ITF image in Java applications. Recognizing GS1128 In C# Using Barcode reader for .NET Control to read, scan read, scan image in Visual Studio .NET applications. Operators and Expressions
EAN13 Generator In None Using Barcode maker for Office Excel Control to generate, create European Article Number 13 image in Microsoft Excel applications. Code128 Drawer In .NET Framework Using Barcode generation for Reporting Service Control to generate, create Code 128C image in Reporting Service applications. So far in this chapter you ve learned that a JavaScript statement is used to tell the browser to do something Many JavaScript statements contain a mathematical expression that tells the browser to perform a mathematical operation Let s pause here, because although math may not be one of your strong points, that shouldn t stop you from learning how to write a mathematical expression Truth is, you already know how to do it Consider the following simple mathematical expression: 2=1+1 Here s another mathematical expression that you ve already seen in this chapter: Data Matrix Creation In None Using Barcode drawer for Microsoft Word Control to generate, create Data Matrix ECC200 image in Microsoft Word applications. Encoding EAN / UCC  13 In Visual Studio .NET Using Barcode drawer for Reporting Service Control to generate, create GS1 128 image in Reporting Service applications. PurchasePrice * 06 European Article Number 13 Generation In Java Using Barcode drawer for BIRT reports Control to generate, create EAN13 Supplement 5 image in Eclipse BIRT applications. Reading Barcode In Visual Basic .NET Using Barcode recognizer for Visual Studio .NET Control to read, scan read, scan image in Visual Studio .NET applications. Now let s take a closer look at how to write an expression
Parts of an Expression
A mathematical expression consists of two parts: operands and operators An operand is the value An operator is the symbol that tells the browser how to evaluate the mathematical expression The operands are the numbers in the following mathematical expression The addition symbol (+) is the operator The browser evaluates this mathematical expression by adding the value on the right side of the operator to the value on the left side of the operator: 1 + 1 Multiple Operations
You might be wondering what happened to the assignment operator (=) in the previous example The assignment operator is another operator requiring the browser to perform another operation The left side of the assignment operator must be a single value The right side can be a single value or an expression, so it can contain multiple values Let s insert the assignment operator into the mathematical expression and see how the second operation is evaluated: = 1 + 1 The browser is now being told to perform two operations The rst operation (mathematical) is to add the value on the left side of the plus sign to the value on the right CHAPTER 2 Variables, Operators, and Expressions
side of the plus sign If you could see the mathematical expression after the rst operation is completed, it would look like this: The browser performs the second operation after the rst operation is completed The second operation uses the assignment operator, which is the equal sign (=) The assignment operator symbol tells the browser to assign the result of the expression on the right side to the value on the left Here s how this mathematical expression looks after the assignment operation is completed: 2 = 2 Performing more than one operation in the same mathematical expression can lead to confusion not for the browser, but for the developer: in what order are the operations performed Two operations were performed in the previous example: addition (+) and assignment (=) operations The browser performed addition before performing the assignment operation How do you know which operation is performed rst You ll need to read the Order of Operations sidebar to answer this question

