Its also known as conditional statement, in c# there are two types of conditional statements. First one is if statement and second one is switch statement. In this article we will learn about if statement, basically if statement depends on condition. If your statement condition is true then if statement is executed otherwise not. Lets take an simple example
Suppose you have a variable a of type int with having some value (take from user input). Like
int a= int.Parse(Console.ReadLine());
Now, if you want to compare this value from other value like 10. Now your statement look like
if(a==10)
{
Console.writeLine("Your Number is 10");
}
So lets analyze this code, Now start from if statement , if statement needs a Boolean expression. In this code , evaluate the expression, which is inside in if bracket. Also return true as well as false Boolean value. If code return true then execute if block. Similarly we create multiple if block like
if(a==10)
{
Console.writeLine("Your Number is 10");
}
if(a==20)
{
Console.writeLine("Your Number is 20");
}
if(a==30)
{
Console.writeLine("Your Number is 30");
}
If user enter any number, if entered number match with among given numbers then compiler display a related message.
Disadvantage of multiple if statement is
if first condition is match with entered value, processed should be closed but in case of multiple if statement, all condition would be checked. You can say its take more time.
So overcome this problem, you must use else-if statement. In case of else-if some false statement will be skipped. Like
if(a==10)
{
Console.writeLine("Your Number is 10");
}
else if(a==20)
{
Console.writeLine("Your Number is 20");
}
If your first condition is true then compiler will not check else-if condition, if first condition returns false then compiler will go to the else statement.
Suppose you have a variable a of type int with having some value (take from user input). Like
int a= int.Parse(Console.ReadLine());
Now, if you want to compare this value from other value like 10. Now your statement look like
if(a==10)
{
Console.writeLine("Your Number is 10");
}
So lets analyze this code, Now start from if statement , if statement needs a Boolean expression. In this code , evaluate the expression, which is inside in if bracket. Also return true as well as false Boolean value. If code return true then execute if block. Similarly we create multiple if block like
if(a==10)
{
Console.writeLine("Your Number is 10");
}
if(a==20)
{
Console.writeLine("Your Number is 20");
}
if(a==30)
{
Console.writeLine("Your Number is 30");
}
If user enter any number, if entered number match with among given numbers then compiler display a related message.
Disadvantage of multiple if statement is
if first condition is match with entered value, processed should be closed but in case of multiple if statement, all condition would be checked. You can say its take more time.
So overcome this problem, you must use else-if statement. In case of else-if some false statement will be skipped. Like
if(a==10)
{
Console.writeLine("Your Number is 10");
}
else if(a==20)
{
Console.writeLine("Your Number is 20");
}
If your first condition is true then compiler will not check else-if condition, if first condition returns false then compiler will go to the else statement.