Hexadecimal to decimal conversion is something that is often needed in hardware. Below functions can be used for hexadecimal to decimal conversion in C:
#include<stdio.h>#include<conio.h>#include<string.h>
int get_value(char a) { if(a>='0'&& a<='9' ) { return (a- '0'); } else if(a>='A' && a<='F') return ((a-'0')-7); } else if(a>='a' && a<='f') return ((a-'0')-39); else return -1;
}
int htoi(char a[]){ int len=strlen(a); int temp=0; for(int i=0;i<len;i++) { int digit=get_value(a[i]); if(digit == -1){ return -1; } temp=temp*16+digit; } return temp;}
int main(){ char a[]="f0"; clrscr(); int b=htoi(a); if(b == -1) printf("invalid input"); else printf("decimal value is %d",b); getch(); return 0;}