Initialization of Arrays

Initialization of Arrays

We can initialize the elements of the array in the same way as the ordinary variables when they are
declared.The general form of initialization of array is:  static  type  array-name [size] = { list of variables};the values in the list are separated by commas.For example, the statement
   static int number [3] = {0,0,0} will declare the variable number as an array of size
3 and will assign zero to each element. If the number of values in the list is less than the number of elements,then only that many elements will be initialized the remaining elements will be set to zero automatically.For instance,
   static float total[5] ={ 0.0, 15.75, -10};
will initialize the first three elements to 0.0, 15.75,
-10 and the remaining two elements to zero.

Note that we have used the word static before type declaration. This declares the variable as a static
variable. The size may be omitted. In such cases the compiler allocates enough space for all initialized  elements.
For example, the statement
     static int counter []={ 1,1,1,1};
   will declare the counter array to contain four elements with initial values 1. This approach works fine as long as we initialize every element in the array.

 Character arrays may be initialized in a similar manner.Thus, the statement
  static char name[] = {J, o ,h , n};
declares the name to be an array of characters,initialized with the string John.

Initialization of arrays in C suffers two drawbacks.1.There is no convenient way to initialize only selected  elements.
2.There is no shortcut method for initializing a large number of array elements like the one available in FORTAN.

Program showing One-Dimensional Array:

 main()
 {
  int i;
  float X[10],value,total;
  print f (Enter 10 real numbers \n);
  for (i=0;i<10;i++)
  {
   scan f(%f ,&value);
   X[i]=value;
  }
  total=0.0;
  for(i=0;i<10;i++)
total =total + X[i] * X[i];
  print f (\n);
  for (i=0;i<10;i++)
  print f( X[%2d]=%5.2f\n, X[i]);
  print f(\n total =%2.f \n , total);
 }

OUTPUT:Enter 10 real numbers
1.2.2 3.3 4.4 5.5 6.6 7.7 8.8 9.9 10.10
 X[1]=1.10
 X[2]=2.20
 X[3]=3.30
 X[4]=4.40
 X[5]=5.50
 X[6]=6.60
 X[7]=7.70
 X[8]=8.80
 X[9]=9.90
 X[10]=10.10
  total= 446.86
consider an array of size ,say 100. All the 100 elements have to be explicitly initialize. There is no way to specify a repeat count. In such situations, it would be better to use a for loop to initialize the elements. Consider the following segment of a C program:
      for(i=0;i<100;i=i+1)
      {
       if(i<50)
       sum[i]=0.0;
       else
       sum[i]=1.0;
      }
  the first 50 elements of the array sum are initialized to zero while the remaining 50 elements are initialized to 1.0.