Vectors A Preview of the Standard Template Library in Software

Creator Data Matrix 2d barcode in Software Vectors A Preview of the Standard Template Library
Vectors A Preview of the Standard Template Library
Making ECC200 In C#
Using Barcode encoder for VS .NET Control to generate, create Data Matrix ECC200 image in .NET applications.
The vector de nition is given in the library vector, which places it in the std namespace Thus, a le that uses vectors would include the following (or something similar):
Making DataMatrix In .NET
Using Barcode drawer for ASP.NET Control to generate, create ECC200 image in ASP.NET applications.
#include <vector> using namespace std;
Data Matrix ECC200 Creation In VS .NET
Using Barcode generator for VS .NET Control to generate, create DataMatrix image in Visual Studio .NET applications.
VECTORS
Generate Data Matrix 2d Barcode In VB.NET
Using Barcode encoder for Visual Studio .NET Control to generate, create Data Matrix image in .NET applications.
Vectors are used very much like arrays, but a vector does not have a fixed size If it needs more capacity to store another element, its capacity is automatically increased Vectors are defined in the library vector, which places them in the std namespace Thus, a file that uses vectors would include the following lines:
Create Code 128 Code Set B In C#.NET
Using Barcode drawer for VS .NET Control to generate, create Code 128B image in VS .NET applications.
#include <vector> using namespace std;
Painting GTIN - 128 In .NET Framework
Using Barcode generator for .NET framework Control to generate, create EAN / UCC - 13 image in .NET applications.
The vector class for a given Base_Type is written vector<Base_Type> Two sample vector declarations are as follows:
UCC - 12 Maker In .NET Framework
Using Barcode drawer for ASP.NET Control to generate, create GS1 - 12 image in ASP.NET applications.
vector<int> v; //default constructor producing an empty vector vector<AClass> record(20); //vector constructor uses the //default constructor for AClass to initialize 20 elements
Encoding Barcode In Visual Studio .NET
Using Barcode printer for VS .NET Control to generate, create bar code image in .NET framework applications.
Elements are added to a vector using the member function push_back, as illustrated below:
Make Data Matrix 2d Barcode In VS .NET
Using Barcode generator for .NET framework Control to generate, create Data Matrix ECC200 image in .NET applications.
vpush_back(42);
Create Code 3/9 In Java
Using Barcode generator for Java Control to generate, create Code 39 Extended image in Java applications.
Once an element position has received its first element, either with push_back or with a constructor initialization, that element position can then be accessed using square bracket notation, just like an array element
Generate Data Matrix In Visual Basic .NET
Using Barcode maker for Visual Studio .NET Control to generate, create Data Matrix ECC200 image in Visual Studio .NET applications.
Pitfall
GS1 - 12 Drawer In Java
Using Barcode drawer for Java Control to generate, create UPC Code image in Java applications.
USING SQUARE BRACKETS
Make Data Matrix ECC200 In Java
Using Barcode printer for Java Control to generate, create Data Matrix 2d barcode image in Java applications.
BEYOND THE
Creating GTIN - 128 In Java
Using Barcode maker for Java Control to generate, create GS1-128 image in Java applications.
VECTOR SIZE
Generating Data Matrix In Visual Studio .NET
Using Barcode generator for ASP.NET Control to generate, create Data Matrix 2d barcode image in ASP.NET applications.
If v is a vector and i is greater than or equal to vsize( ), then the element v[i] does not yet exits and needs to be created by using push_back to add elements up to and including position i If you try to set v[i] for i greater than or equal to vsize( ), as in
Bar Code Creator In Java
Using Barcode creator for Java Control to generate, create barcode image in Java applications.
v[i] = n;
Recognize EAN13 In .NET Framework
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
then you may or may not get an error message, but your program will undoubtedly misbehave at some point
Generate UPC - 13 In Visual Studio .NET
Using Barcode drawer for ASP.NET Control to generate, create GTIN - 13 image in ASP.NET applications.
Constructors and Other Tools
EAN / UCC - 13 Printer In .NET
Using Barcode creator for .NET framework Control to generate, create GTIN - 13 image in .NET applications.
VECTOR ASSIGNMENT IS WELL BEHAVED
Encode Barcode In .NET
Using Barcode generation for .NET Control to generate, create bar code image in .NET framework applications.
The assignment operator with vectors does an element-by-element assignment to the vector on the left-hand side of the assignment operator (increasing capacity if needed and resetting the size of the vector on the left-hand side of the assignment operator) Thus, provided the assignment operator on the base type makes an independent copy of an element of the base type, then the assignment operator on the vector will make an independent copy, not an alias, of the vector on the right-hand side of the assignment operator Note that for the assignment operator to produce a totally independent copy of the vector on the right-hand side of the assignment operator requires that the assignment operator on the base type make completely independent copies The assignment operator on a vector is only as good (or bad) as the assignment operator on its base type
s EFFICIENCY ISSUES
capacity
At any point in time a vector has a capacity, which is the number of elements for which it currently has memory allocated The member function capacity( ) can be used to nd out the capacity of a vector Do not confuse the capacity of a vector with the size of a vector The size is the number of elements in a vector, whereas the capacity is the number of elements for which there is memory allocated Typically the capacity is larger than the size, and the capacity is always greater than or equal to the size Whenever a vector runs out of capacity and needs room for an additional member, the capacity is automatically increased The exact amount of the increase is implementation dependent, but always allows for more capacity than is immediately needed A commonly used implementation scheme is for the capacity to double whenever it needs to increase Because increasing capacity is a complex task, this approach of reallocating capacity in large chunks is more ef cient than allocating numerous small chunks You can completely ignore the capacity of a vector and that will have no effect on what your program does However, if ef ciency is an issue, you may want to manage capacity yourself and not simply accept the default behavior of doubling capacity whenever more is needed You can use the member function reserve to explicitly increase the capacity of a vector For example,
vreserve(32);