Question

There’s a function in C, atoi(), implement this in PHP;

• $string = ‘5467’; //function should return 5467 as integer

So this is what I found (its implementation in C)

int myatoi(const char *string) {
    int i;
    i=0;
    while(*string) {
        i = (i<<3) + (i<<1) + (*string - '0');
        string++;
    }

Answer 1

I don’t know PHP but if the point was to see if you could write the algorithm, I can show how I’d approach this in C. (Untested code here.)

int atoi(char *s)
{
    int val = 0;
    while (*s)
    {
        val *= 10;
        val += (*s) - '0';
        s++;
    }
    return val;
}