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Units of measure are additional type annotations that can be added to floats or integers. They can be used to verify at compile time that calculations are using units consistently. To define annotations: [<Measure>] type m // meters [<Measure>] type s // seconds [<Measure>] typ...

All looping constructs allow the use of break and continue statements. They affect the immediately surrounding (innermost) loop. Basic Loop Control break terminates the loop: for x in 0..5 { if x > 2 { break; } println!("{}", x); } Output 0 1 2 continue finishes...

While many people think that ^ means the start of a string, it actually means start of a line. For an actual start of string anchor use, \A. The string hello\nworld (or more clearly) hello world Would be matched by the regular expressions ^h, ^w and \Ah but not by \Aw

With IronPython you can access any .net assembly which is compiled using the same or a lower version than the IronPython core. Example: Importing a a .net assembly and class from System import Math Example: Using an imported class: from System import Math print Math.Abs(-123) You can also lo...

To find out the IP address of your container, use: docker inspect <container id> | grep IPAddress or use docker inspect docker inspect --format '{{ .NetworkSettings.IPAddress }}' ${CID}

Payments Table CustomerPayment_typeAmountPeterCredit100PeterCredit300JohnCredit1000JohnDebit500 select customer, sum(case when payment_type = 'credit' then amount else 0 end) as credit, sum(case when payment_type = 'debit' then amount else 0 end) as debit from payments group by ...

Maps in go are not safe for concurrency. You must take a lock to read and write on them if you will be accessing them concurrently. Usually the best option is to use sync.RWMutex because you can have read and write locks. However, a sync.Mutex could also be used. type RWMap struct { sync.RWMut...

Java provides several ways to copy an array. for loop int[] a = { 4, 1, 3, 2 }; int[] b = new int[a.length]; for (int i = 0; i < a.length; i++) { b[i] = a[i]; } Note that using this option with an Object array instead of primitive array will fill the copy with reference to the origi...

Variable declaration for examples: Collection<String> abc = Arrays.asList("a", "b", "c"); Collection<String> digits = Arrays.asList("1", "2", "3"); Collection<String> greekAbc = Arrays.asList("alpha", "be...

Two Arrays var array1 = [1, 2]; var array2 = [3, 4, 5]; 3 var array3 = array1.concat(array2); // returns a new array 6 var array3 = [...array1, ...array2] Results in a new Array: [1, 2, 3, 4, 5] Multiple Arrays var array1 = ["a", "b"], array2 = ["...

1 + 2 # Addition 1 - 2 # Subtraction -1 # Set negative value 1 * 2 # Multiplication 1 / 2 # Division 1 % 2 # Modulus 100 -shl 2 # Bitwise Shift-left 100 -shr 1 # Bitwise Shift-right

PowerShell comparison operators are comprised of a leading dash (-) followed by a name (eq for equal, gt for greater than, etc...). Names can be preceded by special characters to modify the behavior of the operator: i # Case-Insensitive Explicit (-ieq) c # Case-Sensitive Explicit (-ceq) Case-I...

Configure your project-level build.gradle to include the android-apt plugin: buildscript { repositories { mavenCentral() } dependencies { classpath 'com.jakewharton:butterknife-gradle-plugin:8.5.1' } } Then, apply the android-apt plugin in your module-level build...

The border-collapse property determines if a tables' borders should be separated or merged. Below an example of two tables with different values to the border-collapse property: The table on the left has border-collapse: separate while the one on the right has border-collapse: collapse. ValueDe...

To previous view controller To pop back to the previous page you can do this: Swift navigationController?.popViewControllerAnimated(true) Objective-C [self.navigationController popViewControllerAnimated:YES]; To root view controller To pop to the root of the navigation stack, you can do...

In your storyboard select the ViewController that you want to embed into a Navigation Controller. Then navigate to Editor > Embed In > Navigation Controller And that will create your navigation controller

You can use the Integer method to convert a String to an Integer: Integer("123") # => 123 Integer("0xFF") # => 255 Integer("0b100") # => 4 Integer("0555") # => 365 You can also pass a base parameter to the Integer method to c...

Android supports several configuration qualifiers that allow you to control how the system selects your alternative resources based on the characteristics of the current device screen. A configuration qualifier is a string that you can append to a resource directory in your Android project and speci...

To add a new column name to the users table, run the command: rails generate migration AddNameToUsers name This generates the following migration: class AddNameToUsers < ActiveRecord::Migration[5.0] def change add_column :users, :name, :string end end When the migration name i...

To add a new indexed column email to the users table, run the command: rails generate migration AddEmailToUsers email:string:index This will generate the following migration: class AddEmailToUsers < ActiveRecord::Migration[5.0] def change add_column :users, :email, :string add_i...