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String to float conversion

Member 8647682 asked:

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Could you please let me know how to convert string to float without using standard functions, like atoi, atof, strtod, sscanf etc.
My code is:
    char inputstr[]="123.45";
    float result= 0.0F;
    float temp;
    int ndecimaldigit,i;
    ndecimaldigit = 1;
        temp=inputstr[i] - '0';
        ndecimaldigit *= 10;
        temp /= ndecimaldigit;
        result += temp;
    printf("%f %f %d \n",result,temp,ndecimaldigit);

But i am getting output as: 0.122671 -0.000129 -31072
which is not correct. I need output as 123.45
Tags: C++, C


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