The Contains()
method checks whether the specified string is present in the string or not.
Example
using System;
namespace CsharpString {
class Test {
public static void Main(string [] args) {
string str = "I love ice cream";
// check if str contains "ice cream"
bool check = str.Contains("ice cream");
Console.WriteLine(check);
Console.ReadLine();
}
}
}
// Output: True
Contains() Syntax
The syntax of the string Contains()
method is:
Contains(String str, StringComparison comp)
Here, Contains()
is a method of class String
.
Contains() Parameters
The Contains()
method takes the following parameters:
- str - string which is to be checked
- comp - ignores or considers case sensitivity
Contains() Return Value
The Contains()
method returns:
- True - if the string contains the specified substring
- False - if the string doesn't contain the specified substring
Example 1: C# String Contains()
using System;
namespace CsharpString {
class Test {
public static void Main(string [] args) {
string str = "I love ice cream";
bool check;
// check if str contains "ice cream"
check = str.Contains("ice cream");
Console.WriteLine("contains ice cream: " + check);
// check if str contains "chocolate"
check = str.Contains("chocolate");
Console.WriteLine("contains chocolate: " + check);
// returns true
check = str.Contains("");
Console.WriteLine("contains \"\": " + check);
Console.ReadLine();
}
}
}
Output
contains ice cream: True contains chocolate: False contains "": True
Here,
str.Contains("ice cream")
- returnsTrue
as str contains"ice cream"
str.Contains("chocolate")
- returnsFalse
as str does not contain"chocolate"
str.Contains("")
- empty string always returnsTrue
Example 2: Contains() With if...else
using System;
namespace CsharpString {
class Test {
public static void Main(string [] args) {
string str = "Ice cream";
// checks if str contains "ice"
if(str.Contains("ice")) {
Console.WriteLine("str contains ice");
}
else {
Console.WriteLine("str does not contain ice");
}
Console.ReadLine();
}
}
}
Output
str does not contain ice
In the above example, str.Contains("ice")
returns False
because the method Contains()
is case sensitive.
Example 3: C# String Contains() Ignore Case
We can also ignore case sensitivity while using Contains()
.
using System;
namespace CsharpString {
class Test {
public static void Main(string [] args) {
string str = "I love ice cream";
bool check;
// considers case sensitivity
check = str.Contains("Ice cream", StringComparison.Ordinal);
Console.WriteLine("considers case sensitivity: " + check);
// ignores case sensitivity
check = str.Contains("Ice cream", StringComparison.OrdinalIgnoreCase);
Console.WriteLine("ignores case sensitivity: " + check);
Console.ReadLine();
}
}
}
Output
considers case sensitivity: False ignores case sensitivity: True
Here,
StringComparison.Ordinal
- considers the letter caseStringComparison.OrdinalIgnoreCase
- ignores the letter case