C language learning Replay organize notes (seven)

Week Seven: Array Operations

C language learning notes

This series of notes is to learn the complex disc Mu class teacher Weng Kai Zhejiang University, "Introduction to Programming Language -C" Note-taking and some of their own conclusion. (Part of the screenshot of the article from the course video screenshot)

Courses link: https: //www.icourse163.org/learn/ZJU-199001 tid = 1206771253 # / learn / content?

7.1 Array Operations

7.1.1 Array Operations

Array is widely used in the search. The search is now a very important application.

Integrated array initialization:

We obtained the array a [0] = 2, the other 12 digits automatic zero-fill.

So, if we want an array initialized to all 0 , we can actually go do not cycle, direct

Cnt [ number ] = {0} ; will all initialized to 0 of

Positioning the integrated initialization

EG2: Int a[10]={ [0]=2, [2]=3,6,};

It is to give a [ 0 ] assigned a 2 ; a a [ 2 ] of assignment 3 ; to a [ 3 ] of assignment 6, the remaining complement to 0.

With n given positioned in the initialized data
No data is positioned behind the contact position in front of
Value of zero padding other locations
May not be given array size, let the compiler count
Particularly suitable for sparse array initialization data

How to get the size of the array?

Sizeof how many bytes the resulting array occupies.

Results after% lu for displaying sizeof

Sizeof (a) / sizeof (a [0]) is an array element occupies

Benefits: Once the initial array data to modify, without modifying the code traversed.

2. array assignment

Not int b [] = a

Array variable itself can not be assigned; put all the elements of an array to another array, you must traverse.

This is the only way to put an array assigned to another array, no other way.

3. The array passed to the function

An array as a parameter, is given in [] is not always the size of the array, write only A [] ; (as shown in the screenshot below)
Inside the function can not be utilized sizeof number of elements in the array to calculate the
We often need to calculate the size of the array is good in the main function with the other parameters, it passed into the function. (As in FIG. Length)