textbook | A JavaScript textbook for web designers | Document Editor library

You need to do things slightly different when you're defining a struct, and when you're instantiating a struct.

When you write:

The following diagram explains your recursive calls tree

• The numbers in blue represent the sequence.
• The conditions in red represent why this call is made.

It works because:

• Circle is accessing public constructor of GenericObject
• the color and filled are parameters of GenericObject constructor used by Circle and not properties of super class GenericObject.
• It would be wrong to say the using super() Circle is accessing the fields of GenericObject. It is setting them using constructor.

You forgot to add a parenthesis to copy. Right now, you just have the copy function assigned to out. It was just referenced, not called. Here is the corrected code.

Because Qiskit has multiple drawers. Those are:

• text
• mpl
• latex
• latex_source.

The drawer you see in the IBM Quantum Lab is the one based on Matplotlib. You can get the same output by qc.draw('mpl').

To set a default, you can change (or create if does not exist) the file ~/.qiskit/settings.conf) with the entry circuit_drawer = mpl.

The command java CreateSpaServices.java you used to execute your program is not meant to be used for programs with multiple source files. It is used to executed single source file java programs without compilation. see JEP330 for more details.

Normally you'd write your Java code, compile it (javac) and afterwards run it (java). You can use the manually or use editor like NetBeans.

So the command you showed above indicates that you use NetBeans just as Editor and don't run nor use the compilation from NetBeans. Which is unclear why.

Normally you'd use NetBeans as your editor and compiler. Means that you write your code within NetBeans and after that you create a jar or class files which can be executed from command line.

When you just want to run the program you can Right Click CreateSpaServices \ Run File to execute the Main method of CreateSpaServices.

The following sets are identical:

• { (−1)^s•f•2^e | s ∈ {0, 1}, f is the value of a 24-bit binary numeral with a radix point after the first digit, and e is an integer such that −126 ≤ e ≤ 127 }.
• { (−1)^s•f•2^e | s ∈ {0, 1}, f is the value of a 24-bit binary numeral with a radix point before the first digit, and e is an integer such that −125 ≤ e ≤ 128 }.
• { (−1)^s•f•2^e | s ∈ {0, 1}, f is the value of a 24-bit binary numeral with a radix point after the last digit, and e is an integer such that −149 ≤ e ≤ 104 }.
• { f•2^e | f is an integer such that |f| < 2²⁴, and e is an integer such that −149 ≤ e ≤ 104 }.

In other words, we may put the radix point anywhere in the significand we want, simply by adjusting the range of the exponent to compensate. Which form to use may be chosen for convenience or preference.

The third form scales the significand so it is an integer, and the fourth form incorporates the sign into the significand. This form is convenient for using number theory to analyze floating-point behavior.

IEEE 754 generally uses the first form. It refers to this as “a scientific form,” reflecting the fact that, in scientific notation, we commonly write numbers with a radix point just after the first digit, as in the mass of the Earth is about 5.9722•10²⁴ kg. In clause 3.3, IEEE 754-2008 mentions “It is also convenient for some purposes to view the significand as an integer; in which case the finite floating-point numbers are described thus:”, followed by text equivalent to the third form above except that it is generalized (the base and other parameters are arbitrary values for any floating-point format rather than the constants I used above specifically for the binary32 format).

A couple of options for you:

1. Explicitly check that user isn't null and throw if it is

2. Define a "logged-in" state interface and write a hook that returns it after checking that user isn't null

3. Define a "logged-in" state interface and write a type assertion function, then use that in Dashboard or the hook

The common theme among them is not just asserting that user isn't null, but proving it at runtime so programming errors using state with null are caught proactively and clearly, rather than being random-seeming "Can't use X of null" errors.

Since the user can only see the Dashboard component if they're signed in, and when they're signed in the user context member won't be null, you can check that explicitly:

You can try using the following regex -