Xcode basic shortcut keys and several common variables

1. Comments

Single-line Comment

/*

Multi-line comments

*/

A single-line comment is generally written in two places, and a single line of comments generally explains what

Why did you do this?

int add (int a,int b) {

Return a+b;//Why did you do this?

}

2, the writing of the head file

#include "header" header file is defined by itself

#include

3. Xcode basic shortcut keys

CTRL + N (next) cursor jumps to the next line

Ctrl+p (Previous) cursor jumps to the previous line

Ctrl+b (back) cursor moves one character to the left

CTRL+F (ForWord) cursor moves one character to the right

Ctrl+h Delete one character to the left of the cursor

Ctrl+d (delete) Delete one character to the right of the cursor

Ctrl+e (end) cursor jumps to end of line

CTRL + A (Ahead) cursor jumps to the beginning of the line

Ctrl+k (Kill) Delete all content to the right of the cursor

Ctrl+i Automatic Formatting

Commond+z back to previous action

Common +/multiple lines of comments or uncomment

Common's +a Select all

4. Variables

The basic unit of computer storage data is byte bytes

1 byte=8 bit

1 in binary notation 0x0000 0001

20 in binary notation 0x0001 0100

Variable type:

Integer variable 4byte=32 bit

int totalman = 2;

printf ("%/d\n", totalman);//Output method

Long Shaping variables

Long Guangnian = 32;

printf ("%/ld\n", Guangnian);

Character Variable 1byte

Char alpha = ' A ';

printf ("%/c\n", Alpha);

Floating-point variable single precision 4byte reserved six digits after the decimal point is omitted

FLOAT score = 90.5;

printf ("%f\n", score);

printf ("%.1f\n", score);

Double Precision 8byte

Double pi= 3.1415926;

printf ("%f\n", pi);

Xcode basic shortcut keys and several common variables