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PHP check whether property exists in object or class
...
property_exists( mixed $class , string $property )
if (property_exists($ob, 'a'))
isset( mixed $var [, mixed $... ] )
if (isset($ob->a))
isset() will return false if property is null
Example 1:
$ob->a = null
var_dump(isset($ob->a)); //...
object==null or null==object?
...e value would be 0 and the article's promise would not hold. The fact that Strings are objects and ints are primitives is irrelevant of the fact that a programmer may forget to init a variable. In this question we simply solve the null String comparison thing.
– cherouvim
...
How do you add an in-app purchase to an iOS application?
... //restored purchases, you can use
//
//NSString *productID = transaction.payment.productIdentifier;
[self doRemoveAds];
[[SKPaymentQueue defaultQueue] finishTransaction:transaction];
break;
}
}
}
- (void)paymentQue...
How do you use the ? : (conditional) operator in JavaScript?
...whole left part: 'Hello ' + username, which is always true, because it's a string with a length greater than 0.
– Jeffrey Roosendaal
Aug 15 '19 at 23:00
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How to get POSTed JSON in Flask?
...quotes while JSON strictly requires double quotes for both the key values (strings) as string values. If you want the JSON representation, use json.dumps() with the object.
– Jochem Schulenklopper
Nov 12 '18 at 15:59
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OpenSSL and error in reading openssl.conf file
...eys
default_md = md5 # message digest algorithm
string_mask = nombstr # permitted characters
distinguished_name = req_distinguished_name
req_extensions = v3_req
[ req_distinguished_name ]
# Variable name Prompt string
#-...
Which cryptographic hash function should I choose?
...challenge-response auth, or for access tokens, or just to index a bunch of strings/files. Performance, on the other hand, is a concern for the OP...
– Seva Alekseyev
May 23 '19 at 17:33
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How to wait until an element exists?
...pecified
* element is inserted into the DOM
* @param {function|string} handler
* A function to execute at the time when the element is inserted or
* string "remove" to remove the listener from the given selector
* @param {bool} shouldRunHandlerOnce
* ...
What is the meaning of “$” sign in JavaScript
...t can be almost anything but is usually "JQuery".
However, in ES6 it is a string interpolation operator in a template "literal" eg.
var s = "new" ; // you can put whatever you think appropriate here.
var s2 = `There are so many ${s} ideas these days !!` ; //back-ticks not quotes
console.log(s2) ;...
What does a lazy val do?
... But it will lead to the same StackOverflowException if your toString method outputs "foo" attribute. Nice example of "lazy" anyway!!!
– Fuad Efendi
Dec 17 '16 at 0:13
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