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POHow to turn null to 0
 

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  1. POHow to turn null to 0
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    <p>I built a little program that calculates the average of 15 numbers or less. There are 15 text-boxes, each one's default value is '0'. The program knows to get the sum of all typed numbers and divide it by numbers of text boxes that don't return '0'. But if the user deletes in mistake one of the '0'os in one of the text boxs.. run-time error.</p> <p>Originally I solved this problam by writing this "<em>if statement</em>" 15 times(one for each text-box):</p> <pre><code> if (t1.Text == "") { tr1 = 0; } else { tr1 = Double.Parse(t1.Text); } </code></pre> <p>this code checks if there isn't a thing in text box(for example, named t1), if true, the program is giving the <em>double</em> 'tr1'(don't confuse with 't1'), the value of '0', if false, the code gives the <em>double</em> 'tr1' the text of 't1'.</p> <p>i had to write this 'if' 15 times. i wanted to know if i can write the same code with arrays and a for loop, and how?</p> <p>here is the whole code (sorry for var names are not similar to var's use.):</p> <pre><code> private void goyouidiot_Click(object sender, EventArgs e) { double tr1; double tr2; double tr3; double tr4; double tr5; double tr6; double tr7; double tr8; double tr9; double tr10; double tr11; double tr12; double tr13; double tr14; double tr15; if (t1.Text == "") { tr1 = 0; } else { tr1 = Double.Parse(t1.Text); } if (t2.Text == "") { tr2 = 0; } else { tr2 = Double.Parse(t2.Text); } if (t3.Text == "") { tr3 = 0; } else { tr3 = Double.Parse(t3.Text); } if (t4.Text == "") { tr4 = 0; } else { tr4 = Double.Parse(t4.Text); } if (t5.Text == "") { tr5 = 0; } else { tr5 = Double.Parse(t5.Text); } if (t6.Text == "") { tr6 = 0; } else { tr6 = Double.Parse(t6.Text); } if (t7.Text == "") { tr7 = 0; } else { tr7 = Double.Parse(t7.Text); } if (t8.Text == "") { tr8 = 0; } else { tr8 = Double.Parse(t8.Text); } if (t9.Text == "") { tr9 = 0; } else { tr9 = Double.Parse(t9.Text); } if (t10.Text == "") { tr10 = 0; } else { tr10 = Double.Parse(t10.Text); } if (t11.Text == "") { tr11 = 0; } else { tr11 = Double.Parse(t11.Text); } if (t12.Text == "") { tr12 = 0; } else { tr12 = Double.Parse(t12.Text); } if (t13.Text == "") { tr13 = 0; } else { tr13 = Double.Parse(t13.Text); } if (t14.Text == "") { tr14 = 0; } else { tr14 = Double.Parse(t14.Text); } if (t15.Text == "") { tr15 = 0; } else { tr15 = Double.Parse(t15.Text); } double[] sch = { tr1, tr2, tr3, tr4, tr5, tr6, tr7, tr8, tr9, tr10, tr11, tr12, tr13, tr14, tr15 }; double total = 0; double sorf = 0; for (int i = 0; i != 14; i++) { sorf = sorf + sch[i]; if (sch[i] &gt; 0) { total++; } } double totalic = sorf / total; string glass = totalic.ToString(); result.Text = ("your score: " + glass); } </code></pre>
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    1. USJohn Saunders
    1. USGilad Naaman
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    1. COWhat if the user enters a Zero in one of the boxes? Would you not end up calculating the wrong average?
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      1. USShravan
    2. COI would use try/catch instead of those if/else cases. This is because, the user can input text too, which will cause an exception, when you try to Double.Parse(tx.Text);.
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      1. USBiroka
    3. COHoly copy/paste code, Batman!
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      1. UScHao
 

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