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Control flow

Simply said, control flow statements allow us to alter the execution of our programs based on certain conditions.

If, if-else, else-if & ternary operator

Used to control the execution based on a singular or limited amount of conditions.

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if (condition) 
{
  // block of code to be executed if the condition is True
}

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if (condition)
{
  // block of code to be executed if the condition is True
} 
else 
{
  // block of code to be executed if the condition is False
}

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if (condition)
{
  // block of code to be executed if condition1 is True
} 
else if (condition2) 
{
  // block of code to be executed if the condition1 is false and condition2 is True
} 
else
{
  // block of code to be executed if the condition1 is false and condition2 is False
}


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variable = (condition) ? expressionTrue :  expressionFalse;

Switch

Used to control the execution based on multiple conditions. The expression gets evaluated once and then the code with the matching case gets executed.

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switch(expression) 
{
  case x:
    // code block
    break;
  case y:
    // code block
    break;
  default:
    // code block
    break;
}

While & do-while loop

Used to keep execution certain statements while the condition evaluates to true. A common way to infinetly loop execution is to use while (true).

The do-while loop will execute atleast once, even if the condition is false.

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while (condition) 
{
  // code block to be executed
}

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do 
{
  // code block to be executed
}
while (condition);

For & foreach loop

Used when you know the specific amount of loops you would like to do.

  • Statement 1: is executed (one time) before the execution of the code block. Usually this is the initialization of some indexer.
  • Statement 2: defines the condition for executing the code block.
  • Statement 3: is executed (every time) after the code block has been executed.
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for (statement 1; statement 2; statement 3) 
{
  // code block to be executed
}

Typically a for-loop looks like this: 

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for (int i = 0; i < 5; i++) 
{
  Console.WriteLine(i);
}

A foreach loop is typically used to go through a collection: 

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foreach (type variableName in arrayName) 
{
  // code block to be executed
}

Break & continue

  • Break: jumps out of a loop
  • Continue: skips one iteration and continues to the next iteration
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while (i < 10) 
{
  if (i == 4) 
  {
    i++;
    continue;
  }
  Console.WriteLine(i);
  i++;
}