在Int Array C＃中更改给定索引处的值

Change value at given index in Int Array C#

我试图创建一个过程来计算给定输入字符串中每个字母的频率。到目前为止，除了在int数组中的给定索引处更新int的值外，我所拥有的代码似乎工作得很好。当我调试代码时，它成功地找到了与当前字符相对应的字符串数组的索引，所以问题似乎出在行：alphabetCount[index] = alphabetCount[index]++;上。

这是密码。

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string[] alphabet = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
int[] alphabetCount = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
string baseInput = string.Empty;

private void button_count1_Click(object sender, EventArgs e)
{
baseInput = textBox_base.Text.ToUpper();
int length = baseInput.Length;

for (int i = 0; i < length; i++)
{
try
{
int index = Array.IndexOf(alphabet,baseInput[i].ToString());
alphabetCount[index] = alphabetCount[index]++;
}
catch
{
//MessageBox.Show("nope");
}
}
}

相关讨论

您可以简化计数器。

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int[] alphabetCount =
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
string baseInput = string.Empty;

private void button_count1_Click(object sender, EventArgs e)
{
baseInput = textBox_base.Text.ToUpper();

foreach(var character in baseInput)
{
if(char.IsLetter(baseInput))
{
// A is ASCII 65, Z is ASCII 90
// Subtract 65 to put it in the alphabetCount range
var index = character - 65;
alphabetCount[index]++;
}
}
}

。

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问题是alphabetCount[index]++首先分配alphabetCount[index]然后增加值。您需要使用预增量运算符来代替：

1	alphabetCount[index] = ++alphabetCount[index];

您可以简单地复制这种行为：

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var arr = new int[2];
arr[0] = arr[0]++;

Console.Write(arr[0]); // 0

号

相关讨论

你只需要写alphabetCount[index]++;或alphabetCount[index] = alphabetCount[index]+1;(相当于)

或者使用LINQ：

1 2	string words ="Hello World"; Dictionary<char, int> counted = words.ToUpper().GroupBy(ch => ch).OrderBy(g => g.Key).ToDictionary(g => g.Key, g => g.Count());

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