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TEA [102]
3 years ago
14

How to add if an statemement on a retrun in react js.

Computers and Technology
1 answer:
miv72 [106K]3 years ago
3 0

Answer:

Of course, if we think about if statement in Javascript or Typescript logic, it’s the same as in every Javascript or Typescript place.

It’s just if/else like pure javascript, but in this case, we won’t talk about the normal if/else.

In react, we’ll need if statements for the one more thing, it’s the rendering.

It’s named “Conditional rendering”, but to make it simple, let’s stay with “if statement in react”.

There are the two most popular ways to use conditional rendering that we’ll see in the React.js code, and depends on a case, both of them are correct.

The first way that we can use is to define the conditional rendering directly in the components layout.

It’s quick and easy that we’ll use the most, and in some cases, it is the best for performance.

We’ll be using this way in the cases when we have only one condition, more just as “if”, when we would like to render some element when a specified condition is passed.

The second way is the function created to handle specified parts of the layout, and render it conditionally, to do that we can use not only if/else but the switch case as well.

This one way is right to use in cases where we have more conditions, especially the version with switch one.

But it fires the function anyway, so it is no sense to use it when we have one condition.

Let’s take a look at the code examples where I added both ways of doing that:

// The first example with the code inside functional component

function Parent(props) {

 return(

   <>

     {name === "Duomly" && (

       <DuomlyComponent/>  

     )}

   </>

 )

}

// The second example with the additional function

function renderComponent() {

 const name = 'Duomly';

 if (name === 'Duomly') {

   return 'Duomly';

 } else {

   return null;

 }

}

function Parent(props) {

 return renderComponent();

}

Explanation:

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Evgesh-ka [11]

Well, Touch screen is only an input device as it only takes the input resistance(or capacitance in new touch screens) value as per the touch on the screen. And this value of resistance would determine the location of the touch on the screen.

The output work is done by the LCD or LED displays, which displays some images and texts on screen.

Touch Screen is only a transparent glass which is place on that display and synchronized with the LED displays such that user is able to 'touch' or have a 'sense of touch' on the actual displays

5 0
3 years ago
When working in Excel Online, which formula will add up the data in cells A1 through A10?
Anuta_ua [19.1K]
The answer is D. The SUM function lets you add all the values along the specified cells. To use the SUM function, you type the equal symbol and the word "sum" then a parenthesis. Inside the parenthesis are the cells you want to add-up. Specify it from the first cell to the last. Add a colon in between to two cell locations. So the right formula to input in finding the sum of all the values from A1 to A10 is =sum(A1:A10).
5 0
4 years ago
Read 2 more answers
Write the printItem() method for the base class. Sample output for below program:
Anna [14]

Answer:

The printItem() method code is filled in the explanation, highlighted with bold font.

Explanation:

// ===== Code from file BaseItem.java =====

public class BaseItem {

  protected String lastName;

  public void setLastName(String providedName) {

      lastName = providedName;

      return;

  }

// FIXME: Define printItem() method

/* Your solution goes here */

  public void printItem() {

      // TODO Auto-generated method stub

      System.out.println("Last name: "+lastName);

  }

}

// ===== end =====

4 0
3 years ago
Using the phase plane program, plot the phase plane for the Lotka-Volterra model:
ivanzaharov [21]

Answer:

yes, the model gives a realistic behavior

Explanation:

This describes the inner equilibrium point is a stable node, here it's a center. These are periodic solutions. Populations of the mice and owls are periodic. It describes: when the mice population is lower, the owl population decreases; again the owl is lower so mice got a chance to grow its population; now as sufficient food(mice) is there, the owl population increases; as predator population increases, the prey population decreases; and this continues as a cycle forever.

So, yes, the model gives a realistic behavior.

Check attachment

7 0
4 years ago
G=D+(A+C^2)*E/(D+B)^3 Rewrite the above formula in terms of doing concurrent processing using cobegin and coend to identify thos
jeka57 [31]

Answer:

G=D+(A+C^2)*E/(D+B)^3

p1:C^2

p2:(D+B)^3

p3:A+p1

p4:E/p2

p5: D+p3+p4

COBEGIN

P1(p1,p2)

COEND

COBEGIN

P2(p3,p4)

COEND

execute p5

Explanation:

P1, P2 are parallel processes as they are independent of each other. And p5 together with P1, P2 forms the serial list of processes, and these must be executed serially.  And we need to run as mentioned above concurrent processes under cobegin and coend. Hence the above is the required list of processes and how they are processed. Concurrent processes are listed under cobegin and coend.

4 0
3 years ago
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