Can't find the bug/probleem in my program : <p>I'm making my first project c++. It's a simple temperature converter.</p>

<p>I made a test section [code 1] with if statements. the if statement would compare the user input. for example if you user typed c and then k(Celsius-Kelvin). it should run the function[code 2] CtoK(); but i doesn't it runs all function why does it do this?</p>

<p>It try to use return but i didn't(it also didn't gave a error so i kept it)</p>

<p>If you guys see something else pls say it <a href="http://pastebin.com/5sGZVKhu" rel="nofollow">Code on pastebin</a></p>

<p>Also thinks to keep it mind:
Just stated to learn C++
Not native English so if there are spelling and grammar mistakes please say it so i can learn form it</p>

<p>[code 1]</p>

<pre><code>void whatToWhat(char firstDegrees, char secondDegrees) {
    if (firstDegrees == 'C' || 'c') {// tests if the user want form c to f
        if (secondDegrees == 'F' || 'f') {
            CtoF();
        }
    }if (firstDegrees == 'C' || 'c') {// tests if the user want form c to k
        if (secondDegrees == 'K' || 'k') {
            CtoK();
        }
    }if (firstDegrees == 'F' || 'f') {// tests if the user want form f to c
        if (secondDegrees == 'C' || 'c') {
            FtoC();
        } 
    }if (firstDegrees == 'F' || 'f') {// tests if the user want form f to k
        if (secondDegrees == 'K' || 'k') {
            FtoK();
        }
    }if (firstDegrees == 'K' || 'k') {// tests if the user want form k to f
        if (secondDegrees == 'F' || 'f') {
            KtoF();
        }
    }if (firstDegrees == 'K' || 'k') {// tests if the user want form k to c
        if (secondDegrees == 'C' || 'c') {
            KtoC();
        }
    }
}
</code></pre>

<p>[code 2]</p>

<pre><code> void CtoF() {// c to f furmula
    double input;
    cout &lt;&lt; "Enter a number[Celsius-Fahrenheit]" &lt;&lt; endl;
    cin &gt;&gt; input;
    cout &lt;&lt; "it's " &lt;&lt; input * 1.8 + 32 &lt;&lt; " Fahrenheit " &lt;&lt; endl;
    return;
}
void CtoK() {// c to k  furmula
    double input;
    cout &lt;&lt; "Enter a number[Celsius-Kelvin]" &lt;&lt; endl;
    cin &gt;&gt; input;
    cout &lt;&lt; "it's " &lt;&lt; input + 273.15   &lt;&lt; " Kelvin " &lt;&lt; endl;
    return;
}
void FtoC() {//f to c furmula
    double input;
    cout &lt;&lt; "Enter a number[Fahrenheit-Celsius]" &lt;&lt; endl;
    cin &gt;&gt; input;
    cout &lt;&lt; "it's " &lt;&lt; input / 1.8 - 32 &lt;&lt; " Celsius " &lt;&lt; endl;

}
void FtoK() {//f to k furmula
    double input;
    cout &lt;&lt; "Enter a number[Fahrenheit-Kelvin]" &lt;&lt; endl;
    cin &gt;&gt; input;
    cout &lt;&lt; "it's " &lt;&lt; input / 1.8 - 32 + 273.15 &lt;&lt; " Kelvin " &lt;&lt; endl;
    return;
}
void KtoF() {// k to f furmula
    double input;
    cout &lt;&lt; "Enter a number[Kelvin-Fahrenheit]" &lt;&lt; endl;
    cin &gt;&gt; input;
    cout &lt;&lt; "it's " &lt;&lt; (input - 273.15) * 1.8 + 32 &lt;&lt; " Fahrenheit " &lt;&lt; endl;

}
void KtoC() {// k to c furmula
    double input;
    cout &lt;&lt; "Enter a number[Kelvin-Celsius]" &lt;&lt; endl;
    cin &gt;&gt; input;
    cout &lt;&lt; "it's " &lt;&lt;273.15 - input &lt;&lt; " Celsius " &lt;&lt; endl;
    return;
}
</code></pre>
