CODEWITHSUNDEEP
javascript
John
John

Reputation: 1189

Explanation needed for this piece of code?

var p = this.getParams();
var pD = (o.params||{});
if (this.useJsonData) pD = (pD.jsonData||{});
this.cursor = (pD && pD[p.start]) ? pD[p.start] : 0;

And what is the difference between these two lines. 

this.cursor = pD[p.start] || this.cursor || 0;

Is the first code fine or there is any fault in it.

Upvotes: -1

Views: 72

Answers (2)

Sean Hogan
Sean Hogan

Reputation: 2920

Look at this page: https://developer.mozilla.org/en/JavaScript/Guide/Expressions_and_Operators

Search for conditional operator, logical operators and short-circuit evaluation.

Upvotes: -1

Sergio Tulentsev
Sergio Tulentsev

Reputation: 230531

Your second line has a fault. What if pD is null? Also it will keep value of this.cursor that is true (not null or false, that is).

Otherwise, they are identical.

Upvotes: 0

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