Use of Int32.Parse(), Convert.ToInt32(), and Int32.TryParse()

Int32.Parse (string val)

This method converts string representation of the integer into it's 32-bit signed integer. 

val is null - throw ArgumentNullException.

val is not an integer - throw FormatException.

val is less than MinValue or greater thanMaxValue - throw OverflowException.

string val1 = "356"; 

string val2 = "abc"; 

string val3 = null; 

string val4 = "123456789123456789123456789123456789123456789"; 

int result; 

result = Int32.Parse(val1); //-- 1234 

result = Int32.Parse(val2); //-- FormatException 

result = Int32.Parse(val3); //-- ArgumentNullException 

result = Int32.Parse(val4); //-- OverflowException

Convert.ToInt32(string val)

This method converts string representation of the integer into it's 32-bit signed integer. 

val is null - return 0.

val is not an integer - throw FormatException.

val is less than MinValue or greater thanMaxValue - throw OverflowException.

result = Int32.Parse(val1); //-- 1234 

result = Int32.Parse(val2); //-- FormatException 

result = Int32.Parse(val3); //-- 0

result = Int32.Parse(val4); //-- OverflowException 

Int32.TryParse(string, out int)

This method converts string representation of the integer into it's 32-bit signed integer to a out variable and returns true if parsing succeed.

val is null - return 0.

val is not an integer - return 0.

val is less than MinValue or greater thanMaxValue - return 0.

bool result;

result = Int32.Parse(val1, out result); //-- true, result->1234 

result = Int32.Parse(val2, result); //-- false, result->0

result = Int32.Parse(val3, result); //-- false, result->0

result = Int32.Parse(val4, result); //-- false, result->0

TryParse is the fastest method from above mentioned options.