Left function in c# [duplicate]

This question already has answers here: .NET equivalent of the old vb left(string, length) function (11 answers) 开发者_Python百科 Closed 3 years ago.

what is the alternative for Left function in c# i have this in

Left(fac.GetCachedValue("Auto Print Clinical Warnings").ToLower + " ", 1) == "y");

---

It sounds like you're asking about a function

string Left(string s, int left)

that will return the leftmost left characters of the string s. In that case you can just use String.Substring. You can write this as an extension method:

public static class StringExtensions
{
    public static string Left(this string value, int maxLength)
    {
        if (string.IsNullOrEmpty(value)) return value;
        maxLength = Math.Abs(maxLength);

        return ( value.Length <= maxLength 
               ? value 
               : value.Substring(0, maxLength)
               );
    }
}

and use it like so:

string left = s.Left(number);

For your specific example:

string s = fac.GetCachedValue("Auto Print Clinical Warnings").ToLower() + " ";
string left = s.Substring(0, 1);

---

It's the Substring method of String, with the first argument set to 0.

 myString.Substring(0,1);

[The following was added by Almo; see Justin J Stark's comment. —Peter O.]

Warning: If the string's length is less than the number of characters you're taking, you'll get an ArgumentOutOfRangeException.

---

Just write what you really wanted to know:

fac.GetCachedValue("Auto Print Clinical Warnings").ToLower().StartsWith("y")

It's much simpler than anything with substring.

---

use substring function:

yourString.Substring(0, length);

---

var value = fac.GetCachedValue("Auto Print Clinical Warnings")
// 0 = Start at the first character
// 1 = The length of the string to grab
if (value.ToLower().SubString(0, 1) == "y")
{
    // Do your stuff.
}