freeCodeCamp/guide/english/certifications/javascript-algorithms-and-data-structures/basic-javascript/compound-assignment-with-augmented-subtraction/index.md

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Compound Assignment With Augmented Subtraction

Compound Assignment With Augmented Subtraction

Computers read from left to right. So, using the '-=' operator means that the variable is subtracted by the number on the right, then the variable is assigned to the difference. Like so:

var b = 10;
b -= 4; // Now, 'b' is 6