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Numbers

Numbers are represented by simple numerals. They can have a decimal point and a minus sign.
var x1 = 1;
var x2 = 1.0;
var x3 = 3.14;
var x4 = -1;
1 and 1.0 are the same number. You can calculate with numbers. The four basic arithmetics adding, subtracting, multiplying and dividing are represented by + - * and /.
var x1 = 6;
var x2 = 2;
var x3 = x1 + x2;
var x4 = x1 - x2;
var x5 = x1 * x2;
var x6 = x1 / x2;
The variables x3 to x6 thus have the values 8, 4, 12 and 3.

Exercise

Write a function add that takes two numbers and returns their sum. add(1, 2) should return 3.
var add = function(x, y) {
  return ...
};
var add = function(x, y) {
  return x + y;
};