It's easy in Javascript to know how many characters are in string using the property .length.
// Just use the property .length
var size = 'Our lovely string'.length;Note: Strings can not be substracted, multiplied or divided.
{% exercise %}
Store in the variable named size the length of str.
{% initial %}
var str = "Hello World";
var size = {% solution %} var str = "Hello World";
var size = str.length; {% validation %} assert(size === str.length); {% endexercise %}