Private fields C# with Example

There are two common conventions for private fields: camelCase and _camelCaseWithLeadingUnderscore. 
Camel case 
public class Rational 
{ 
private readonly int numerator; 
private readonly int denominator; 
public Rational(int numerator, int denominator) 
{ 
// "this" keyword is required to refer to the class-scope field 
this.numerator = numerator; 
this.denominator = denominator; 
} 
} 
Camel case with underscore 
public class Rational 
{ 
private readonly int _numerator; 
private readonly int _denominator; 
public Rational(int numerator, int denominator) 
{ 
// Names are unique, so "this" keyword is not required 
_numerator = numerator; 
_denominator = denominator; 
} 
}