CompareTo. This method acts upon 2 values (like strings or numbers). It returns an int value. The returned value (-1, 1 or 0) tells us which of the 2 numbers is bigger.
When using CompareTo, we usually return directly the value of the method call. This enables us to easily implement comparisons for sorting in C#.
Input and output. A negative one indicates the first value is smaller. A positive one indicates the first value is bigger. And a zero indicates the two values are equal.
5.CompareTo(6) = -1 First int is smaller.
6.CompareTo(5) = 1 First int is larger.
5.CompareTo(5) = 0 Ints are equal.
An example. This program uses 3 int values. Next, the variables "ab", "ba", and "ca" contain the results of the ints "a", "b", and "c" compared to one another.
Here We see that when the first number is larger, the result is 1. When the first number is smaller, the result is -1.
And When the numbers are equal, the result is 0. These values are written to the console.
using System;
class Program
{
static void Main()
{
const int a = 5;
const int b = 6;
const int c = 5;
int ab = a.CompareTo(b);
int ba = b.CompareTo(a);
int ca = c.CompareTo(a);
Console.WriteLine(ab);
Console.WriteLine(ba);
Console.WriteLine(ca);
}
}-1
1
0
Uses. The CompareTo method is most useful in implementing sorting routines. We use CompareTo when implementing IComparable, Comparison delegate target methods, and Comparisons with lambdas.
A summary. CompareTo provides a standard way to determine which of two numbers is larger. The result tells us if a number comparison is larger, smaller, or equal.
Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.
Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.
This page was last updated on Nov 12, 2022 (edit).
