91. Explain about array declaration and initialization for different data types.

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For one dimensional array, the elements are accessed by using array name followed by an index within a square bracket. For example: if an array is declared as: int num[5]; then num[0], num[1] are used to access first and second element respectively.

For two dimensional array, the elements are accessed using array name followed by two square

bracket within which row index and column index should be given. For example: if an array is

declared as: int list[3][3]; then to access the value we use list[0][1] to access the value of first row and second column.

Assuming, Array declaration and initialization: int num[5] = {1 , 2, 3, 4, 5}; And a function check() to do some operation.

Here, we can see that, in function declaration and definition the square brackets are not required but square brackets with index are required in function call when single element is passed. On the other hand, there is a presence of square bracket without index in function declaration and definition while passing complete array. And in function call, only the name of an array is passed without pair of square brackets. Since name of an array represents the address of first element, it exhibits pass by reference whereas passing single element represent pass by value.

(array name) represents pass by reference”, explain the statement with example.

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only, passing in such way symbolizes passing by value. But when array name is passed, it passes the starting address of an array, as we know that name of an array represents the address of first element. For example, passing array name num to the function represents passing of the address of num[0]; as num = &num[0]. Using that base address, all other elements can be accessed. Hence passing array name or complete array represents pass by reference.

Let us take an example to demonstrate string constants and variable. char name[20] = “Johnson”;

Here, the variable name is declared as array of characters, which can be used as a string variable.

But to use it as a string variable, it must be assigned a string constant or a set of characters with a null character at the end. The set of characters defined within double quotation marks is a string constant. There will be a default null character in a string constant. While string formed from set of characters must be terminated with null character manually.

96. How are string declared? Demonstrate the different ways of initializing strings.

char str[10]; here, str is a string variable.

Stings are initialized as

Size of an array is optional, when strings are initialized in the declaration. The size of the string will be equal to the number of elements. If size needs to be declared then it must be equal or greater than the number of characters initialized.

Different ways of reading a string are as follows.

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scanf(“%[^n]”, string_variable); reads characters unless new line is detected.

while(string_variable[i]!=’n’)

{

string_variable[i] = getchar();

i++;

}

string_variable[i] = ‘’;

98. Explain why address operator (ampersand) is not used while reading a string?

99. Describe the general form, purpose, and return value (if any) of the following string functions:

strlen(), strcat(), strcpy(), strcmp()

char string_name[number_of_strings][Number of characters in each string];

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char namelist[10][20]; it represents an array of strings with total 10 strings with each 20 characters long.

char namelist[10][10] =

In two dimensional declarations of arrays of characters, if the variable is followed with two pair of square brackets then it represents a single character. For instance, namelist[1][1] represents the character ‘a’. In simple, it selects the second row and then second column, pointing to character ‘a’. But if the variable is followed with single pair of square brackets then it represents a string. For example, namelist[2] symbolizes a string “Holmes”.