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POReturning a substring using c++ within a class
 

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    <p>SO I have a substring function that takes in the start location of the substring and its length. With that it should extract the characters within and return them as a string, without actually using any string function.</p> <pre><code>//default constructor that sets the initial string to the value "Hello World" MyString::MyString() { char temp[] = "Hello World"; int counter(0); while(temp[counter] != '\0') { counter++; } Size = counter; String = new char [Size]; for(int i=0; i &lt; Size; i++) String[i] = temp[i]; } //copy constructor MyString::MyString(const MyString &amp;source) { int counter(0); while(source.String[counter] != '\0') { counter++; } Size = counter; String = new char[Size]; for(int i = 0; i &lt; Size; i++) String[i] = source.String[i]; } </code></pre> <p>Here is my substring function:</p> <pre><code>MyString MyString::Substring(int start, int length) { char* leo = new char[length+1]; for(int i = start; i &lt; start + length+ 1; ++i) { leo[i-start] = String[i]; } MyString sub; delete [] sub.String; sub.String = leo; sub.Size = length+1; return sub; } </code></pre> <p>With this code from the main.cpp file:</p> <pre><code> int main (int argc, char **argv) { MyString String1; // String1 must be defined within the scope const MyString ConstString("Target string"); //Test of alternate constructor MyString SearchString; //Test of default constructor that should set "Hello World". MyString TargetString (String1); //Test of copy constructor cout &lt;&lt; "Please enter two strings. "; cout &lt;&lt; "Each string needs to be shorter than 256 characters or terminated by /\n." &lt;&lt; endl; cout &lt;&lt; "The first string will be searched to see whether it contains exactly the second string. " &lt;&lt; endl; cin &gt;&gt; SearchString &gt;&gt; TargetString; // Test of cascaded string-extraction operator if(SearchString.Find(TargetString) == -1) { cout &lt;&lt; TargetString &lt;&lt; " is not in " &lt;&lt; SearchString &lt;&lt; endl; } else { cout &lt;&lt; TargetString &lt;&lt; " is in " &lt;&lt; SearchString &lt;&lt; endl; cout &lt;&lt; "Details of the hit: " &lt;&lt; endl; cout &lt;&lt; "Starting position of the hit: " &lt;&lt; SearchString.Find(TargetString) &lt;&lt; endl; cout &lt;&lt; "The matching substring is: " &lt;&lt; SearchString.Substring(SearchString.Find(TargetString), TargetString.Length()-1)&lt;&lt;"\n"; } </code></pre> <p>It returns:</p> <p>Please enter two strings. Each string needs to be shorter than 256 characters or terminated by / . The first string will be searched to see whether it contains exactly the second string.</p> <p>forever</p> <p>more</p> <p>morev World is not in forever</p> <p>Any thoughts on why it actually isn't outputting the words from user input without the extra characters? I'm lost.</p>
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    1. COWhat is `String[i]` in the code? Are you calling `operator []` on `this`?
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    2. COTried a debugger? Do `SearchString` and `TargetString` have the contents you expect? Do `Find` and `Length` return the values you expect?
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    3. CO@mlt String is the String in the class, so I'm guessing you are right.
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