Lectii de Informatica
All numeric and date data types in Visual Basic contain the ToString method. This method converts the contents of a variable to a string.
In this video tutorial you will learn about Explicit Type Conversion. If Option Strict is set to On and you try to perform anything other than a widening conversion, your code will not compile. Visual Basic has a set of conversion functions to solve this problem. The following situations require a
In this video tutorial you will learn about Named Constants. A named constant is like a variable and cannot be changed by a programming statement while the program is running. It looks like a regular variable declaration except for the following differences:
In this video tutorial you will learn about literals. Literals (also known as constants) are values which are not changing in the programe and have specific types in Visual Basic. Many literals use a suffix character (C-char, D-decimal, R-double, I-integer, L-long, F-single, S-short, !-single) to identify their type.
In this video tutorial you will learn how to set Option Strict. Visual Basic has a configuration option named Option Strict that determines whether certain implicit data type conversions are legal. If you set Option Strict to On, only widening conversions are permitted (such as Integer to Double). If, on the other hand, Option Strict is set to Off, all types of numeric conversions are permitted, with possible loss of data.
In this video tutorial you will learn about Implicit Type Conversion. When one value of a data type is assigned to a variable of another data type is known as an Implicit Type Conversion. Implicit conversion between numeric types must be in a left-to-right direction. A Decimal value can be assigned to a variable of type Single, an Integer can be assigned to a variable of type Double, and so on, as follow:
In this video tutorial you will learn about Grouping with Parentheses.The mathematical expressions can be grouped with parentheses to force some operations to be performed before others.
In this video tutorial you will learn about the operator precedence. Mathematical expressions are evaluated from left to right. When two operators share an operand, the operator with the highest precedence executes first.
In this video tutorial you will learn about Combined Assignment Operators.
In this video tutorial you will learn how to get the current date and time. Your computer system has an internal clock that calculates the current date and time. Visual Basic provides the functions which allow you to retrieve the current date, time, or both from your computer.
In this video tutorial you will learn about arithmetic operators. To do this I created a very simple calculator application.Visual Basic has powerful arithmetic operators that perform calculations with numeric variables and literals.
In this Visual Basic video tutorial you will learn about variables.Variables hold data that may be manipulated, used to manipulate other data.A variable is a storage location in computer memory that holds data while a program is running. Integer Data Types Integers are whole numbers such as -10, 2, 6350, and 0. Visual Basic has four data types:
In this video tutorial you will learn how to move cursor to one of the form's controls using Focus method. To do this I used an application from previous video tutorial and I added a new code line that will move the cursor to first Text Box control of the form.
In this video tutorial you will learn how to display message using MessageBox.Show(). It displays a pop-up message window. To do this, I used application form the previous video tutorial.
In this video tutorial you will learn how to input and to display message using Text Box. To do this, I created a simple application in Visual Basic that contains three buttons, and three Text Box Controls. In the first two Text Box Controls you will introduce dates and the third text box control will display dates introduced.