C tutorial : C Language Refresher

C tutorial : C Language Refresher

Sample of the pdf document :

Variables and Types

C is a statically-typed, imperative language. Variables and their types must be declared before use.

double pi = 3.14159265358979;

float x = 0.5;

char c = ’a’;

int a = 42;

int b;

e values of variables change, but not the types.

a = a * 10;

b = a + 1;

Structure and Array Types

Structures are groups of values behaving as a single variable.

struct city

{

int population;

float latitude;

float longitude;

};

Arrays are contiguous blocks of values, all of the some type.

int n[10];

struct city capitals[50];

Pointer

A C pointer is an address in RAM.

int i = 10; // i is a normal integer variable.

int *p = &i; // p refers to the location of i.

e & operator gives “the address of ” a variable

i = 42;

*p = 42;

e * operator gives “the variable at” an address.

Pointers

A C string is a pointer to a zero-terminated array of chars.

char *filename = "teapot.obj"

Pointers and arrays are interchangeable.

int a[10];

int *p = a;

a[5] = 12;

p[5] = 12;

Functions

Functions are declared with arguments and return type.

int average(int a, int b)

{

return (a + b) / 2;

}

Calling this function. . .

x = average(2, 8);

Conditionals

if (value == 0)

{

answer = "false";

}

else

{

answer = "true";

}

Rememb

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C tutorial : C Language Refresher