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An array is a list of data items that all have the same type and the same name?
An array element has the same type as the array name.
What is the importance of array?
Arrays are important because we often need to work with a collection of variables of the same type and, particularly with large collections, it would be impractical to declare and name each one individually. With an array we don't have to name them because the variables are allocated in contiguous memory addresses and every element is the same length. Knowing only the start address of the array and the zero-based index of an element we gain constant-time random access to any element in the array. An array is really just an extension of a type. When we declare a variable of a given type we allocate sufficient memory to hold just one object of that type. With an array, we can allocate as many objects as we require.
What is traversing arrays?
Traversing an array simply means visiting every element of the array exactly once. Pointers facilitates this job. A pointer is first created to contain the base address of the array thereby pointing the first element. As the pointer is incremented, it points to the very next element and so on till the last element is visited. Thus the elements are visited sequentially in the same order as they are stored in the array.
What an array?
An array is an aggregate of data elements of the same type. Arrays are allocated in contiguous memory. An element of an array can be another array type, also known as a multi-dimensional array.
How 3d arrays are represented in memory?
All multi-dimensional arrays are represented as arrays of arrays. That is, each element of the array is itself an array. Thus a two-dimensional array can be thought of as being a one-dimensional array where every element is a one-dimensional array. A three-dimensional array is therefore a one-dimensional array of two-dimensional arrays. And so on. The actual memory layout of a multi-dimensional array is no different to that of a one-dimensional array of the same size: int a[12]; int b[3][4]; Assuming a 4-byte int, the amount of memory allocated to a is 12 x 4 = 48 bytes. The array b is essentially an array where each element holds an array of 4 integers, thus each element is 16 bytes in length. Given there are 3 such elements in total, the total size of b is 3 x 16 = 48 bytes, the same as was allocated to a. Although the allocations are exactly the same in terms of size, the layouts differ. The array a is an array of twelve 4-byte elements (of type int) whereas array b is an array of three 16-byte elements, each of which is itself an array of four 4-byte elements (of type int). This changes the way we refer to the individual elements of the array. Every element in an array is referred to by its offset address from the start of the array. This is determined by multiplying its zero-based index by the element size. In the case of a, every element is 4-bytes in length, thus element a[2] refers to the element that is offset 2 x 4 = 8 bytes from the start of the array. But in the case of b, however, b[2] would refer to the 16-byte element that is offset 2 x 16 = 32 bytes from the start of the array. Given that we're actually referring to an element which is itself a 4-element array, we must use a second subscript to refer to the elements of that array. Thus b[2][3] would refer to the integer that is offset 3 x 4 bytes from the start of the array referred to by b[2]. Extending this idea into three-dimensions is simply a matter of taking a third subscript into account.
Is passing an array to a function exactly the same as passing a pointer to the first element?
Yes it is
What is the difference between null array and an empty array?
There is no null array as such. However, a pointer to an array may be nullified (pointing to zero) before memory is allocated to it, or after that memory is released. But the same is true of any pointer. That is, the pointer is NULL, not what it previously pointed to. An empty array usually refers to a dynamic array for which no memory has yet been allocated (in other words, a null pointer). However, the term can also apply to static arrays or dynamic arrays that have been allocated memory, where every element is initialised with a value that has no significance. For instance, an array of natural numbers (positive integers greater than 0) might be initialised with the value 0 (a non-natural number) in every element to indicate that the array is empty. By contrast, individual elements could be set to zero to indicate which elements are available (an empty element as opposed to an empty array).
What will happen if you try to write to an array element larger than your array?
The results of that programming error is undefined. You must NEVER EVER write, or EVEN READ an array element beyond the allocated size of the array. Period.I would flunk a student that consistently did this, and I would fire a programmer that did the same.
Why you use loop in arrays in c plus plus?
We use loops with arrays because it's one the simplest methods of traversing an array. since each element in an array is the same size, every element can be access via an offset from the start of the array, using the array suffix operator []. Arrays employ zero-based offsets because the first element is always at the same address as the array itself. Thus the first element is at offset [0], while the third is at offset [2]. What this means is that if we multiply the size of an element by its offset index, we can determine the address of that element and therefore access that element's value. The subscript operator does this for us automatically, thus giving us constant-time random access to any element in the array. We can also use pointers to manually calculate the address of an element (which is what actually goes on behind the scenes). However, when we wish to traverse the array, one element at a time, a loop is the simplest method of doing so. The loop simply iterates through all the offset indices, beginning with offset 0, then 1, and 2, and so on. The final index is always 1 less than the number of elements in the array, because arrays are zero-based.
How are array functions useful?
Programs typically operate upon sequences of data. It would be impractical to provide names or references to every single element in a sequence, but arrays allow us to refer to a sequence of any length through a single name or reference to the first element. All other elements are referenced by their offsets, which can be easily calculated at runtime because every element of an array is the same length and all elements are allocated contiguously; all we need to know is the zero-based index of the element we are interested in. Calculating an offset address takes the same amount of time regardless of the index, thus we get constant-time random-access to any element. Naming a large set of variables is tedious, however we often have no idea how many variables we require at runtime, particularly when those variables are generated from a variable-length input, making it impossible to name each one individually. With an array we don't have to name them, we simply allocate as much memory as is required and refer to the elements by their offset address from the start of the array. the only two pieces of information we need are the start address and the length of the array (in elements). An array of n elements has indices in the range 0 to n-1, inclusive.
Passing an array name to a pointer assigns the first memory location of the array to the pointer variable?
Yes, passing an array name to a pointer assigns the first memory location of the array to the pointer variable. An array name is the same as a pointer to the first location of the array, with the exception that an array name is a r-value, while a pointer is an l-value.
Insert an element after an element in an array?
To begin, obtain the element to be added, such as x Then, say pos, get the position where this element will be put. Then shift the array items one position ahead, then do the same for all the other elements next to pos. Because the location pos is now empty, insert the element x there. To learn more about data science please visit- Learnbay.co
