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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Build a Quiz Challenge, Part 2 Solution

Christopher Wallace
Christopher Wallace
6,277 Points
Posted by Christopher Wallace
Christopher Wallace
6,277 Points

why does he use the html += in the answer,, I'm confused to why is not just html + ????

why does he use the html += in the answer,, I'm confused to why is not just html + ????

2 Answers

Damien Watson
Damien Watson
27,419 Points
Damien Watson
Damien Watson
27,419 Points

Hi Christopher,

The += is shorthand, used to set this variable equal to itself plus the item on the right. Easier to explain in code:

var html = "<p>Hey there ";
html += "John!</p>";             // == "<p>Hey there John!</p>"

// If he just used `html +` he would have to add `html = ` before it to get the same result:
var html = "<p>Hey there ";
html = html + "John!</p>";

// You also have -=, *=, /= which again is shorthand.
// This can apply to numbers as well.

var sum = 10;    // sum = 10
sum += 10;       // sum = 20       -- sum = sum + 10
sum /= 5;        // sum = 4         -- sum = sum / 5