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POfunction parameter used to store value
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  1. POfunction parameter used to store value
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    copied!<p>I have to define an interface. The API in my homework is stated below:</p> <pre><code>int generate_codes(char * ssn, char * student_id); </code></pre> <p>int denotes 0 or 1 for pass or fail. studentid is an output param should return a 6 digit id. ssn is a 9 digit input param</p> <p>they school program will take ssn's and use my code to generate the student id. </p> <ol> <li>now from an API perspective should I not be using const char * for both parameters.</li> <li>should the studentid not be passed in by reference? rather than by pointer?</li> <li>can someone tell me how i can easily use the pointer in my test app which uses my api to get the pointer such that it prints a std::string from a char *? </li> </ol> <p>my app code looks something like</p> <pre><code>const char * ssn = "987098765" const char * studnt_id = new char [7]; int value = -1; value = generate_codes(ssn,studnt_id); std::string test(studnt_id); std::cout&lt;&lt;"student id= "&lt;&lt;test&lt;&lt;" Pass/fail= "&lt;&lt;value&lt;&lt;std::endl; delete [] studnt_id; return 0; </code></pre> <p>I basically got an error about &lt;&lt; not being compatible with the right hand side of the operand. When i changed the code to </p> <pre><code>std::cout&lt;&lt;"student id= "&lt;&lt;test.c_str()&lt;&lt;" Pass/fail= "&lt;&lt;value&lt;&lt;std::endl; </code></pre> <p>then it worked but i get garbage for the value. not sure how to do get the value form the pointer. THe value inside the function prints just fine. but when i try to print it outside of the function it prints garbage. Inside the above function I do set the studndt_id like so</p> <pre><code>std::string str_studnt_id = studnt_id; </code></pre> <p>this is to take a string param to my real funciton that does the code generation. when I am ready with the code and want to return it i do the following:</p> <pre><code>studnt_id = str_studnt_id.c_str(); </code></pre> <p>should that make the address of the str_studnt point to the address of studnt_id and thus any changes I make to the value that its pointing to it should reflect outside the function? This API is used using char * but my functions use std::string.</p>
 

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