The first day of IOS learning, and the first day of IOS Learning

Source: Internet
Author: User

The first day of IOS learning, and the first day of IOS Learning

Originally engaged in. NET developers have been reluctant to switch to IOS. After complicated inner struggles, they finally have the courage to resign and study IOS. Now they have become unemployed and add students and dogs. I hope that after four months of study, I can get the desired salary. The following are the learning notes during the learning process. In order to make it easier for you to view them in the future, and also hope to provide some help for IOS beginners, you are prepared to record the learning notes for IOS throughout the learning phase.

IOS Learning (C Language) knowledge point sorting notes in the first week

 

---------------- Notes on the first day ------------------

1. Mac terminal operation commands

 

1) The tab key can be automatically filled

 

2) command name + [Command Options] + [command parameters]

 

3) pwd shows the path of the current directory/File

 

4) ls displays the files and Folder Information in the current folder.

 

5) ls-a displays all the files and folders in the current folder, including hidden files.

 

6) cd enters the file or folder cd + directory name cd .. the parent directory is returned.

 

7) create a folder mkdir + folder name

 

8) touch creates a file touch + file name

 

9) cat displays the file content cat + file name

 

10) cp copy file cp-rf copy folder

(Note: When copying a file/folder, it must be in the directory path where the current file/folder is located)

 

11) rm delete file rm + file name rm-rf Delete folder (note the current directory)

 

12) change the file/folder name in the mv mobile file or folder mv + file name/folder name path + target path mv

Mv + original file/folder name + new file/folder name

 

Vim Editor

13) The vim + file name enters the file editing command mode.

13-1) "I" inserts text before the current cursor

13-2) "a" inserts text after the current cursor

13-3) "o" inserts a new line of text under the current cursor

13-4) "O" inserts text on the current cursor

 

14) Press Esc to exit the editing mode.

 

15) in vim editing mode, move the cursor to the text and press the x key to delete the text.

 

16) in vim editing mode, undo the change by u

 

17): set number display row number: set nonmember close row number display

 

18) copy a row yy copy multiple lines xyy cut one LINE dd cut multiple lines xdd paste p

 

19) w: Save the current edited content: q! Exit and do not save the edited content: wq saves the edited content and exits: wq! Save the edited content and exit.

 

GCC compiler

20) touch test. c. Create a test file and write the Execution Code.

 

21) gcc-o test. c compile the test file

 

22)./test run the compiled test

 

 

2. Common Xcode shortcut keys

1) CMD +,: Set

2) CMD + R: Run

3) CMD +/: comment a line. Uncomment

4) CMD +]: Right Shift of the code segment

5) CMD + [: Move the code segment to the left

6) CMD + Z: Undo operation

 

4. main function: the main function. For any C program, each sentence of the main function must end;

 

5./**/used to comment out multiple lines of code // used to comment out a single line of code

 

6. In the main function, printf declares in stdio. h to press the Alt key + Click the left mouse button to jump to view the specific implementation.

 

7. <> Search for the header file "" in the database. Search for the header file locally. If not, search for the header file in the database.

 

8. int indicates that the number of main rows returns an integer value.

 

9. Description of formatted strings

 

1) \ n indicates the carriage return character \ d indicates the Tab character

 

2) % d indicates a 10-digit integer

 

3) % f indicates float %. 2f indicates that two decimal places are retained.

 

4) % s indicates the string type char arr []

 

5) % c indicates a single character type char

 

6) % hd indicates short integer short

 

7) % lf indicates double Precision Floating Point Type

 

8) % Lf indicates long double Type Dual-precision floating point long double Type

 

9) % ld indicates long integer long

 

10) % lld indicates the long type

 

11) % u indicates an unsigned decimal integer unsigned int

 

12) % lu indicates a signed long integer unsigned long

 

13) % o indicates an unsigned octal node.

 

14) % x indicates an unsigned hexadecimal integer

 

15) printf ("Format String", parameter). The number of parameters that a string must contain double quotation marks must strictly correspond to the format and number of formatted strings.

 

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