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Check if string contains only whitespace

How can I test if a string contains only whitespace? 11 Answers 11 ...
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How to calculate time elapsed in bash script?

...ers of detail, from bash-hackers.org: %(FORMAT)T outputs the date-time string resulting from using FORMAT as a format string for strftime(3). The associated argument is the number of seconds since Epoch, or -1 (current time) or -2 (shell startup time). If no corresponding argument is suppl...
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Given a class, see if instance has method (Ruby)

..., not just methods. For example: Given an instance of a class that has a String attribute first_name: <instance>.first_name.class #=> String <instance>.class.method_defined?(:first_name) #=> true since first_name is both an attribute and a method (and a string of type String)...
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How do you switch pages in Xamarin.Forms?

...Type) { var viewName = viewModelType.FullName.Replace("Model", string.Empty); var viewAssemblyName = GetTypeAssemblyName(viewModelType); var viewTypeName = GenerateTypeName("{0}, {1}", viewName, viewAssemblyName); return Type.GetType(viewTypeName); } publ...
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What permission do I need to access Internet from an Android application?

...Backup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.example.exp.MainActivity" android:label="@string/app_name" > <intent-filter> <acti...
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What's the nearest substitute for a function pointer in Java?

... Anonymous inner class Say you want to have a function passed in with a String param that returns an int. First you have to define an interface with the function as its only member, if you can't reuse an existing one. interface StringFunction { int func(String param); } A method that takes...
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Calculating days between two dates with Java

...asses. DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd MM yyyy"); String inputString1 = "23 01 1997"; String inputString2 = "27 04 1997"; try { LocalDateTime date1 = LocalDate.parse(inputString1, dtf); LocalDateTime date2 = LocalDate.parse(inputString2, dtf); long daysBetween =...
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Regex group capture in R with multiple capture-groups

... str_match(), from the stringr package, will do this. It returns a character matrix with one column for each group in the match (and one for the whole match): > s = c("(sometext :: 0.1231313213)", "(moretext :: 0.111222)") > str_match(s, "\\...
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How to make a new List in Java

...eate a list that has things in it (though it will be fixed size): List<String> messages = Arrays.asList("Hello", "World!", "How", "Are", "You"); share | improve this answer | ...
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When and why to 'return false' in JavaScript?

...s, such as onsubmit, returning false is a way to tell the event to not actually fire. So, say, in the onsubmit case, this would mean that the form is not submitted. share | improve this answer ...