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POWhy isn't this while loop exiting?
 

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  1. POWhy isn't this while loop exiting?
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    <p>I wrote a console program to help me test a function library I coded. Part of it is this piece of code:</p> <pre><code>char insertChoice[2] = {'9'}; while (insertChoice[0] != '0') { cout &lt;&lt; "\nEnter a string:\n"; char insertStringInput[256]; cin.getline(insertStringInput, 255); char insertChoice[2]; insertChoice[0] = '9'; cout &lt;&lt; "\nWhere would you like to insert the substring?\n\n 1) At the beginning of the string\n 2) At the end of the string\n\nInput: "; cin &gt;&gt; insertChoice; cin.ignore(); while (insertChoice[0] != '1' &amp;&amp; insertChoice[0] != '2') { cout &lt;&lt; "\nInvalid input.\nWhere would you like to insert the substring?\n\n 1) At the beginning of the string\n 2) At the end of the string\n\nInput: "; cin &gt;&gt; insertChoice; cin.ignore(); } cout &lt;&lt; "\nEnter the substring you would like to insert: "; char insertSubstring[256]; cin.getline(insertSubstring, 255); std::string used = "", substr = ""; used += insertStringInput; substr += insertSubstring; char insertOutputChoice[2]; insertOutputChoice[0] = '1'; if (insertChoice[0] == '1') insertOutput(insertInBeginning(used, substr)); else insertOutput(insertInEnd(used, substr)); cin &gt;&gt; insertOutputChoice; cin.ignore(); if (insertOutputChoice[0] == '1') { ofstream outfile("logfile.txt", ios::app); outfile &lt;&lt; "Test type: Insert Substring\n"; outfile &lt;&lt; "Test carried out on: " &lt;&lt; __DATE__ &lt;&lt; "; " &lt;&lt; __TIME__ &lt;&lt;"\n"; outfile &lt;&lt; "PARAMETERS:\n"; outfile &lt;&lt; "usedString: \"" &lt;&lt; insertStringInput &lt;&lt; "\"\n"; outfile &lt;&lt; "insertString: \"" &lt;&lt; insertSubstring &lt;&lt; "\"\n"; outfile &lt;&lt; "function used: " &lt;&lt; (insertChoice[0]=='1'?"insertInBeginning":"insertInEnd") &lt;&lt; "\nOUTPUT:\n"; outfile &lt;&lt; "\"" &lt;&lt; (insertChoice[0]=='1'?insertInBeginning(used, substr):insertInEnd(used, substr)) &lt;&lt; "\"\n\n"; outfile.close(); cout &lt;&lt; "\nWould you like to do another string insertion test? [y/n]: "; char insertConfirm[2]; insertConfirm[0] = ' '; while (tolower(insertConfirm[0]) != 'y' &amp;&amp; tolower(insertConfirm[0] != 'n')) { cin &gt;&gt; insertConfirm; cin.ignore(); if (tolower(insertConfirm[0]) != 'y' &amp;&amp; tolower(insertConfirm[0] != 'n')) cout &lt;&lt; "\nInvalid input. Would you like to do another string insertion test? [y/n]: "; } if (insertConfirm[0] == 'n') insertChoice[0] = '0'; } } </code></pre> <p>However, the <code>while (insertChoice[0] != '0')</code> loop does not exit when the user types in <code>insertOutputChoice</code> as 1, regardless of whether the user types in <code>insertConfirm</code> as <code>y</code> or <code>n</code> even though it is supposed to exit when <code>insertConfirm</code> is typed in as <code>n</code>.</p> <p><code>insertOutput</code> looks as looks as follows:</p> <pre><code>void insertOutput(std::string substrOut) { cout &lt;&lt; "\nThe new string generated is:\n"; cout &lt;&lt; substrOut; cout &lt;&lt; "\n\n1) Generate a log file of this test\n"; cout &lt;&lt; "2) Insert another substring into a string\n\n"; cout &lt;&lt; "0) Finish testing string insertion\n\n\n"; cout &lt;&lt; "Input: "; } </code></pre> <p>Please excuse the messy, unoptimized code. My first priority is to get this done, and I usually leave optimization until last.</p>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USGerome Schutte
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    2. PO
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    3. PO
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    1. This table or related slice is empty.
    1. COHave you stepped through the code in a debugger and examined the variable's values?
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      1. POWhy isn't this while loop exiting?
      1. USOldProgrammer
    2. COYes. The `if (insertConfirm[0] == 'n') insertChoice[0] = '0';` does change the value of insertChoice, but when the while criteria is evaluated, insertChoice[0] changes back to '9' until the code inside the while starts executing again.
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      1. POWhy isn't this while loop exiting?
      1. USGerome Schutte
 

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