query: How to check if a JavaScript variable is NOT undefined?
positive_passages.docid: 80608
positive_passages.text: JavaScript check if variable exists (is defined/initialized)
negative_passages.docid: 80984
negative_passages.text: How do I check if an HTML element is empty using jQuery?
negative_passages.docid: 53586
negative_passages.text: How can I type-check variables in Python?
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negative_passages.text: What is the scope of variables in JavaScript?
negative_passages.docid: 137660
negative_passages.text: Avoid running the script if a variable is not defined
negative_passages.docid: 121296
negative_passages.text: How to pass the value 'undefined' to a function with multiple parameters?
negative_passages.docid: 576
negative_passages.text: How can I check for an empty/undefined/null string in JavaScript?
negative_passages.docid: 55996
negative_passages.text: How can I know if a node is already defined?
negative_passages.docid: 113018
negative_passages.text: Javascript shorthand if
negative_passages.docid: 45164
negative_passages.text: Do 'if' statements in JavaScript require curly braces?
negative_passages.docid: 93047
negative_passages.text: How to check whether a variable is a class or not?
negative_passages.docid: 126341
negative_passages.text: Avoiding IF ELSE due to variable been NULL
negative_passages.docid: 95117
negative_passages.text: How do I pass variables to JavaScript?
negative_passages.docid: 84421
negative_passages.text: variable === undefined vs. typeof variable === "undefined"
negative_passages.docid: 40229
negative_passages.text: How do I check if a variable exists?
negative_passages.docid: 14660
negative_passages.text: Undefined variable as function argument javascript
negative_passages.docid: 27606
negative_passages.text: Detecting an undefined object property