Good day for all ;) Can anyone help me to find algorithms or already resolved solutions for comparing strings like SQL do it.
For instance In SQL I can compare strings for
= or <=, >, < e.t.c.
In C# as known we can't do it.
I want to compare something like
"aa" > "b" "ab" < "aa" "abc" >= "bca" and so on..
Also, maybe someone knows by what logic SQL does it?
Strings implement IComparable, so you can use CompareTo.
void Main()
{
if ("a".CompareTo("b") < 0)
{
Console.WriteLine("A is less than B");
}
if ("a".CompareTo("b") <= 0)
{
Console.WriteLine("A is less than or equal to B");
}
if ("a".CompareTo("a") == 0)
{
Console.WriteLine("A equals A");
}
if ("c".CompareTo("b") > 0)
{
Console.WriteLine("C is greater than B");
}
if ("c".CompareTo("b") >= 0)
{
Console.WriteLine("C is greater than or equal to B");
}
}
However, if you want case-insensitive comparison then you will need to use the overload of string.Compare that allows you to ignore case. The logic is the same though.
null? null.CompareTo(...) throws an exception.
Well, "aa" < "ab" equals to
bool result = String.Compare("aa", "ab") < 0;
and so on:
// "abc" >= "bca"
bool result = String.Compare("abc", "bca") >= 0;
the general pattern for "left" <=> "right" is
String.Compare("left", "right") <=> 0
since String.Compare(left, right) returns
left < rightleft == rightCompare(left, right) returns positive value (> 0) if left greater than right, it returns zero if left equals to right, and negative value when left less than right.