This is the 11th day of my participation in the August More Text Challenge. For details, see:August is more challenging

1. variable
2. The operator
3. C language statement
4. An array of
5. function
6. Pointer to the
7. The structure of the body

## 05 Part Five Variables

Variables are the quantities that can be changed during the running of the program, such as y,z,w, etc.

• Definition method:

Data type variable 1[, variable 2…] For example:

``````int a=0;
double b=0.23;
charS = 'A';int *a =0x2323;
Copy the code``````
• Initialization: An initial value is given when defined
• Position of variable definition: usually at the beginning of the function

## 06 Part Six operator

### Arithmetic operator

Assuming variable A = 10 and variable B = 20, then:

### An operator

The bitwise and &, bitwise or | and bitwise exclusive or ^ truth table is as follows:

### Assignment operator

The assignment operator assigns the value on the right to the variable on the left.

### Other operators

In addition, there are relational operators, namely >, ≥, ≤, <,! =, == (what is an equal sign? Two equals again?) In which, the first four take precedence over the last two. In particular, the priority is from high to low. Arithmetic operator > relational operator > assignment operator

## Part Seven C language statements

### C Statement type

C language is divided into the following five categories:

• Control statement: such as loop statement while, for, such as conditional statement if, such as branch statement switch.
• Function call statement: consists of a function call plus a semicolon.
``````int main(a)
{ int Min(int a,int b){
if(a>b){
returnb; }else{returna; }}}Copy the code``````
• Expression statement: Add a semicolon to the end of an expression, such as assignment statement a=a+1.
• Empty statement: A statement that contains only one semicolon, that is, {}.
• Compound statement: A sequence of statements enclosed by curly braces {}.

### Control statements

#### If statement:

• sample

{/ statement to execute if the expression is true /}

• For example:
``````main(){
int a=1, b=2;
if(a < b) { ++a; }}
Copy the code``````
• Result: if a is less than B, a increases by 1 and becomes 2.

#### If else statement:

• sample

If (expression){/ statement that will execute if the expression is true /} else{/ statement that will execute if the expression is false /}

• For example,
``````main(){
int a=1, b=2;
if(a < b) { ++a; }
else{a*=4; }}Copy the code``````
• Result: if a is less than b, then a increases by 1 and becomes 2; otherwise, a is equal to a times 4.

### Goto statement

#### Break statement:

• For example:
``````for(int i=0; i<N; ++i){
if(i == 2)
break;
}
Copy the code``````
• Result: The loop is terminated directly when I is 2.

#### The continue statement:

• For example,
``````for(int i=0; i<N; ++i){
if(i == 2)
continue; }Copy the code``````
• Result: When I is 2, this cycle is finished and the next decision is made.

## 08 Part Eight Array

### An array of concepts

• Int a[100]; // Define an array of 100 integers; • Array: an ordered collection of data elements of the same type;
• 1. The name common to an array;
• 2. A variable in a collection;
• Array dimension: The number of subscripts following the array name;
• Array element format: array name [subscript];
• Array definition: < data type > < Array name >[< constant expression >]={< initial value >}

### A few points to note

Int a[5]={1,2,3}; //a[0]=1,a[1]=2,a[2]=3,a[3]=0,a[4]=0. Note: Arrays can be defined and initialized, not defined and initialized, as follows:

Array, a two dimensional array data type > < < name > / < 1 > constant expression (< 1 > constant expression) = {< initial value >} : float c [3] [3], then the following elements:

In terms of memory, a two-dimensional array is actually an array of one-dimensional arrays.