Take It Away explainer


#1

The aim of this puzzle: Use the subtraction assignment -= operator to subtract from a variable.

Walkthrough of the solution: When updating the value of a variable, a new value must be assigned to the variable. The usual way to do this would be something like:

let x = 5;
x = x - 2;

This tells the code, “Take the current value of x (which is 5), subtract 2, and reassign it to x.” x would now equal 3.

A shorter way to write this is to use the -= operator:

let x = 5;
x -= 2;

Is the same as:

let x = 5;
x = x - 2;

To complete this puzzle, use the -= operator to subtract purchase from wallet.

Sample code solution:
(Tap below to reveal)

let wallet = 80;
let purchase = 35;

wallet -= purchase;
console.log('Wallet is now ' + wallet);

JavaScript Concepts: Subtraction Assignment Operator, Variable Declarations with Let