How to check if a word starts with a given character?

问题

I have a list of a Sharepoint items: each item has a title, a description and a type. I successfully retrieved it, I called it result. I want to first check if there is any item in result which starts with A then B then C, etc. I will have to do the same for each alphabet character and then if I find a word starting with this character I will have to display the character in bold.

I initially display the characters using this function:

private string generateHeaderScripts(char currentChar)
{
    string headerScriptHtml = "$(document).ready(function() {" +
        "$(\"#myTable" + currentChar.ToString() + "\") " +
        ".tablesorter({widthFixed: true, widgets: ['zebra']})" +
        ".tablesorterPager({container: $(\"#pager" + currentChar.ToString() +"\")}); " +
        "});";
    return headerScriptHtml;
}

How can I check if a word starts with a given character?

回答1:

To check one value, use:

    string word = "Aword";
    if (word.StartsWith("A")) 
    {
        // do something
    }

You can make a little extension method to pass a list with A, B, and C

    public static bool StartsWithAny(this string source, IEnumerable<string> strings)
    {
        foreach (var valueToCheck in strings)
        {
            if (source.StartsWith(valueToCheck))
            {
                return true;
            }
        }

        return false;
    }

    if (word.StartsWithAny(new List<string>() { "A", "B", "C" })) 
    {
        // do something
    }

AND as a bonus, if you want to know what your string starts with, from a list, and do something based on that value:

    public static bool StartsWithAny(this string source, IEnumerable<string> strings, out string startsWithValue)
    {
        startsWithValue = null;

        foreach (var valueToCheck in strings)
        {
            if (source.StartsWith(valueToCheck))
            {
                startsWithValue = valueToCheck;
                return true;
            }
        }

        return false;
    }

Usage:

    string word = "AWord";
    string startsWithValue;
    if (word.StartsWithAny(new List<string>() { "a", "b", "c" }, out startsWithValue))
    {
        switch (startsWithValue)
        {
            case "A":
                // Do Something
                break;

            // etc.
        }
    }

回答2:

You could do something like this to check for a specific character.

public bool StartsWith(string value, string currentChar) {
   return value.StartsWith(currentChar, true, null);
}

The StartsWith method has an option to ignore the case. The third parameter is to set the culture. If null, it just uses the current culture. With this method, you can loop through your words, run the check and process the word to highlight that first character as needed.

回答3:

Assuming the properties you're checking are string types, you can use the String.StartsWith() method.. for example: -

if(item.Title.StartsWith("A"))
{
    //do whatever
}

Rinse and repeat

回答4:

Try the following below. You can do either StartsWith or Substring 0,1 (first letter)

    if (Word.Substring(0,1) == "A") {
    }

回答5:

To return the first character in a string, use:

Word.Substring(0,1) //where word is a string

回答6:

You could implement Regular Expressions. They are quite powerful, but when you design your expression it will actually accomplish a task for you.

For example finding a number, letter, word, and etc. it is quite expressive and flexible.

They have a really great tutorial on them here:

An example of such an expression would be:

string input = "Some additional string to compare against.";
Match match = Regex.Match(input, @"\ba\w*\b", RegexOptions.IgnoreCase);

That would find all the items that start with an "a" no matter the case. You find even utilize Lambda and Linq to make them flow even better.

Hopefully that helps.

来源：https://stackoverflow.com/questions/15527051/how-to-check-if-a-word-starts-with-a-given-character

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sharepoint

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