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How can I determine if a JavaScript variable is defined in a page? [duplicate]
How can i check in JavaScript if a variable is defined in a page? Suppose I want to check if a variable named "x" is defined in a page, if I do if(x != null) , it gives me an error.
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What is the best way to compare floats for almost-equality in Python?
...dds the math.isclose and cmath.isclose functions as described in PEP 485.
If you're using an earlier version of Python, the equivalent function is given in the documentation.
def isclose(a, b, rel_tol=1e-09, abs_tol=0.0):
return abs(a-b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
rel_...
Checking if a key exists in a JS object
...ust an object.
You can use the hasOwnProperty method to check for a key:
if (obj.hasOwnProperty("key1")) {
...
}
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iOS detect if user is on an iPad
...iPad and everything but there needs to be one adjustment. I need to detect if the current device is an iPad. What code can I use to detect if the user is using an iPad in my UIViewController and then change something accordingly?
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How to represent multiple conditions in a shell if statement?
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Classic technique (escape metacharacters):
if [ \( "$g" -eq 1 -a "$c" = "123" \) -o \( "$g" -eq 2 -a "$c" = "456" \) ]
then echo abc
else echo efg
fi
I've enclosed the references to $g in double quotes; that's good practice, in general. Strictly, the parentheses ar...
Limit Decimal Places in Android EditText
...anage your finances. I'm using an EditText Field where the user can specify an amount of money.
37 Answers
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Difference between VARCHAR and TEXT in MySQL [duplicate]
...e stored string.
cannot be (fully) part of an index. One would need to specify a prefix length.
VARCHAR(M)
variable max size of M characters
M needs to be between 1 and 65535
takes 1 + c bytes (for M ≤ 255) or 2 + c (for 256 ≤ M ≤ 65535) bytes of disk space where c is the length of the sto...
How to fix Array indexOf() in JavaScript for Internet Explorer browsers
If you have worked with JavaScript at any length you are aware that Internet Explorer does not implement the ECMAScript function for Array.prototype.indexOf() [including Internet Explorer 8]. It is not a huge problem, because you can extend the functionality on your page with the following code.
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MySQL, Check if a column exists in a table with SQL
I am trying to write a query that will check if a specific table in MySQL has a specific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception.
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How to create CSV Excel file C#? [closed]
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Slightly different version I wrote using reflection for my needs. I had to export a list of objects to csv. In case someone wants to use it for future.
public class CsvExport<T> where T: class
{
public List<T> ...