write array declaration for the scores of 100 students
Answers
This line of code from the sample program declares an array variable:
int[] anArray; // declare an array of integers
Like declarations for variables of other types, an array declaration has two components: the array's type and the array's name. An array's type is written type[], where type is the data type of the elements contained within the array, and [] indicates that this is an array. Remember that all of the elements within an array are of the same type. The sample program uses int[], so the array called anArray will be used to hold integer data. Here are declarations for arrays that hold other types of data:
float[] anArrayOfFloats;
boolean[] anArrayOfBooleans;
Object[] anArrayOfObjects;
String[] anArrayOfStrings;
You can write an array declaration like this:
float anArrayOfFloats[]; //this form is discouraged
However, convention discourages this form because the brackets identify the array type, and so they should appear with the type designation, not with the array name.
As with declarations for variables of other types, the declaration for an array variable does not create an array and does not allocate any memory to contain array elements. The code must create the array explicitly and assign it to anArray.
Creating an Array
You create an array explicitly using Java's new operator. The next statement in the sample program allocates an array with enough memory for ten integer elements and assigns the array to the variable anArray declared earlier.
anArray = new int[10]; // create an array of integers
In general, when creating an array, you use the new operator, plus the data type of the array elements, plus the number of elements desired enclosed within brackets—[ and ].
new elementType[arraySize]
If the new statement were omitted from the sample program, the compiler would print an error like the following one and compilation would fail.
ArrayDemo.java:4: Variable anArray may not have been initialized.
Array Initializers
You can use a shortcut syntax for creating and initializing an array. Here’s an example:
boolean[] answers = { true, false, true, true, false };
The length of the array is determined by the number of values provided between { and }.
Accessing an Array Element
Now that some memory has been allocated for the array, the program assign values to the array elements:
for (int i = 0; i < anArray.length; i++) {
anArray[i] = i;
System.out.print(anArray[i] + " ");
}
This part of the code shows that to refer to an array element, either to assign a value to it or to get its value, you append brackets to the array name. The value between the brackets indicates (with a variable or other expression) the index of the element to access.
Getting the Size of an Array
To get the size of an array, you