 In the preceding video, we had this flowchart for characterizing your amount of exercise depending on the percentage of your maximum heart rate. Here's the code we came up with. A multi-way if-else statement, as the book calls it, or an if-else-if chain. And here it is in action. A percentage of 92.3% is a maximum workout. 67% is a light workout and 58.2% is very light. Beginning programmers often wonder why they need to do an if-else-if chain. Why not write it like this with separate if statements? Let's see what that looks like in action. Again, a percentage of 92.3% is maximum. A percentage of 67 prints out three things, not one, and the percentage of 58.2 gives us four lines of output instead of one. Why is there such a big difference between the two versions? To answer that, let's go back to the correct version and expand it to a version with all the braces, and use 67% as our input. 67 is not less than or equal to 60, which means we take the else clause. 67 is less than or equal to 70, which means we do the if clause and the program prints light, and we don't take the else clause, which contains all the other possibilities. Here's what that looks like in the shorter if-else-if chain version. Now let's go to the separate if version that doesn't work. I'll put lines between the if statements to emphasize that they are really separate. And again, we'll set our percent to 67. 67 is not less than or equal to 60, and the program doesn't print very light. That if statement has concluded. We have a brand new if statement. 67 is less than 70, the program prints light, and that if statement has concluded. We go to a completely new if statement. 67 is less than 80, and the program prints moderate. That if statement has concluded. We move on to the last if statement. 67 is less than 90, the program prints hard, and it skips the last else clause. And that's the difference between an if-else-if chain where each if is dependent on the results of the preceding entries and a series of separate if statements where each decision is independent of the others. Make sure you choose the right one for the effect you want your program to have.