C

turn a char into an int in c

int x = character - '0'; 

casting an int to a char in c

Use ASCII chart.
int i=65;
char ch;
ch= (char)i;
printf("Expected value of ch: A. This value is found by using a ASCII chart");

c int to char

int i = 7;
char str[256];

itoa(i,str,10); //Base 10

char c = str[0]; // c="7"

int to char in c

c = i +'0';