Assign value of multiple char array elements to int

This is a discussion on Assign value of multiple char array elements to int within the C Programming forums, part of the General Programming Boards category; Code: int x char text[10] = {"123456789"}; how do I assign the values in array elements text[3] and text[4] to ...

  1. #1
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    Assign value of multiple char array elements to int

    Code:
    int x
    char text[10] = {"123456789"};
    how do I assign the values in array elements text[3] and text[4] to int so int will equal 45?

  2. #2
    cwr
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    Code:
    /* silly way, converting each element to an integer */
    x = (text[3]-'0') * 10 + (text[4]-'0');
    
    /* slightly less silly way */
    char new[16] = { 0 };
    strncpy(new, text + 3, 2); /* copy text[3] and text[4] to new */
    new[2] = '\0'; /* null terminate new */
    x = atoi(new); /* or use strtol for error checking */

  3. #3
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    Another simple way. Not very efficient when you want to do several characters.
    Code:
    int x
    char text[10] = {"123456789"};
    x = text[3] - '0' + text[4] - '0';

  4. #4
    cwr
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    Ancient Dragon, that's the way I suggested above, except I multiplied the first term by 10. Your way just adds them, producing 9, not 45.

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