training-js-number-7-if-dot-else-and-ternary-operator

Training JS #7: if..else and ternary operator

In Javascript, if..else is the most basic condition statement, it consists of three parts:condition, statement1, statement2, like this:

if (condition) statementa
else           statementb

It means that if the condition is true, then execute the statementa, otherwise execute the statementb.If the statementa or statementb more than one line, you need to add { and } at the head and tail of statement in JS, to keep the same indentation on Python and to put a end in Ruby where it indeed ends.

An example, if we want to judge whether a number is odd or even, we can write code like this:

public static string OddEven(final int n){
  if (n%2==1) return "odd number";
  else        return "even number";
}

If there is more than one condition to judge, we can use the compound if...else statement. an example:

public static string OldYoung(final int age){
  if (age<16)      return "children";
  else if (age<50) return "young man";   //use "else if" if needed
  else             return "old man";
}

This function returns a different value depending on the parameter age.

Looks very complicated? Well, JS and Ruby also support the ternary operator and Python has something similar too:

condition ? statementa : statementb

Condition and statement separated by "?", different statement separated by ":" in both Ruby and JS; in Python you put the condition in the middle of two alternatives. The two examples above can be simplified with ternary operator:

public static string OddEven(final int n){
  return n%2==1 ? "odd number" : "even number";
}
public static string OldYoung(final int age){
  return age<16 ? "children" : age<50 ? "young man" : "old man";
}

Task:

Complete function saleHotdogs/SaleHotDogs, function accept 1 parameters:n, n is the number of customers to buy hotdogs, different numbers have different prices (refer to the following table), return a number that the customer need to pay how much money.

+---------------+-------------+
|  numbers n    | price(cents)|
+---------------+-------------+
|n<5            |    100      |
+---------------+-------------+
|n>=5 and n<10  |     95      |
+---------------+-------------+
|n>=10          |     90      |
+---------------+-------------+

You can use if..else or ternary operator to complete it.

When you have finished the work, click "Run Tests" to see if your code is working properly.

In the end, click "Submit" to submit your code pass this kata.