C Language Learning Tutorials fourth-arrays (4)

Initialization of two-dimensional arrays
Two-dimensional array initialization is also assigned an initial value to each subscript variable in the type description. Two-dimensional arrays can be assigned in rows or rows, and can be assigned sequentially. For example, array a[5][3]:
1. Assignment by row segment can be written as static int a[5][3]={{80,75,92},{61,65,71},{59,63,70},{85,87,90},{76,77,85}};
2. Continuous assignment by row can be written as static int a[5][3]={80,75,92,61,65,71,59,63,70,85,87,90,76,77,85};
The results of these two initial assignments are exactly the same.
void Main ()
{
int i,j,s=0,l,v[3];
static int a[5][3]={{80,75,92},{61,65,71},{59,63,70},
{85,87,90},{76,77,85}};
for (i=0;i<3;i++)
{for (j=0;j<5;j++)
S=s+a[j][i];
V[I]=S/5;
s=0;
}
L= (V[0]+v[1]+v[2])/3;
printf ("Math:%d\nc languag:%d\ndbase:%d\n", v[0],v[1],v[2]);
printf ("total:%d\n", L);
}
The following instructions are also available for initializing a two-dimensional array:
1. You can only assign an initial value to part of the element, and the element that does not have initial values automatically takes 0.
Example: Static int a[3][3]={{1},{2},{3}}; is to assign a value to the first column of each row, and an unassigned element takes a value of 0. The values of each element after assignment are: 1 0 02 0 03 0 0
static int A [3][3]={{0,1},{0,0,2},{3}}; The value of the assigned element is 0 1 00 0 23 0 0
2. If an initial value is assigned to all elements, the length of the first dimension may not be given.
For example: static int a[3][3]={1,2,3,4,5,6,7,8,9}; Can be written as: static int a[][3]={1,2,3,4,5,6,7,8,9};
An array is a constructed type of data. A two-dimensional array can be thought of as a nested array of one-dimensional arrays. Each element of a one-dimensional array is an array, and a two-dimensional array is formed. Of course, the prerequisite is that each element type must be the same. Based on this analysis, a two-dimensional array can also be decomposed into multiple one-dimensional arrays. The C language allows this decomposition to have two-dimensional array a[3][4], which can be decomposed into three one-dimensional arrays whose array names are a[0],a[1],a[2]. You can use these three one-dimensional arrays without further explanation. These three one-dimensional arrays have 4 elements, for example: the elements of a one-dimensional array a[0] are a[0][0],a[0][1],a[0][2],a[0][3]. It must be emphasized that a[0],a[1],a[2] cannot be used as subscript variables, they are array names, not a simple subscript variable.

Character array

The array used to hold the character quantity is called a character array. The character array type description is the same as the numeric array described earlier. For example: Char c[10]; Because the character and integral types are universal, you can also define int c[10] But at this point each array element occupies 2 bytes of memory unit. A character array can also be a two-dimensional or multidimensional array, for example: Char c[5][10], or a two-dimensional character array. A character array also allows initialization of an assignment when the type description is used. For example: Static char c[10]={' C ', ', ' P ', ' R ', O ', G ', R ', ' A ', ' m '}; The value of each element after assignment is: array c c[0]c[1]c[2]c[3]c[4]c [5]c[6]c[7]c[8]c[9] c[ 9] is not assigned, and is automatically assigned a value of 0 by the system. The length description can also be omitted when an initial value is assigned to the whole element. For example: Static char c[]={' C ', ', ' P ', ' r ', ' O ', ' g ', ' r ', ' A ', ' m ', when the length of the C array is automatically set to 9.
Main ()
{
int i,j;
Char a[][5]={{' b ', ' A ', ' s ', ' I ', ' C ',},{' d ', ' B ', ' A ', ' s ', ' E '}};
for (i=0;i<=1;i++)
{
for (j=0;j<=4;j++)
printf ("%c", A[i][j]);
printf ("\ n");
}
}
The two-dimensional character array of this example is given an initial value as all elements are initialized, so the length of the one-dimensional subscript can not be explained. The string does not have a special string variable in the C language, and it usually holds a string with a character array. When describing string constants in the 2.1.4 section, it has been stated that the string always ends with ' I ' as a string. So when a string is stored in an array, the Terminator is also stored in an array and is used as a flag for whether the string ends. With the ' I ' flag, it is no longer necessary to use the length of the character array to determine the length of the string.
The C language allows you to initialize the array with a string of values. For example:
static char c[]={' C ', ', ' P ', ' r ', ' O ', ' g ', ' r ', ' A ', ' m '}; Can be written as:
static char c[]={"C Program"}; or remove {} write as:
Sratic Char c[]= "C program";