For if statements, the C# code looks like this:
if (X == 50)
{
Y = 20;
}
The IL language will look like this (here, we are adding the line numbers for branching instructions):
00: ldloc.0 //load local variable 0 (X)
01: ldc.i4.s 50 //load int32 constant with value 50 into the stack
02: bne 5 //if not equal, branch/jump to line number 5
03: ldc.i4.s 20 //load int32 constant with value 20 into the stack
04: stloc.1 //place the value 20 from the stack to the local variable 1 (Y)
05: nop //here, it could be any code that goes after the If statement
06: nop