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.

Store in the variable named size the length of str.

var str = "Hello World";

var size =

var str = "Hello World";

var size = str.length;

assert(size === str.length);