Now my trial component has been past propped how can I use them? For a component to receive its props, it has to know about the minutes function arguments. Props are passed as an object. So we have three options here. We can just pass the props object as a single argument to the arrow function like shown here. To use the specific props value inside the component, say header text, we need to prefix it with the props dot notation. 

Here's an example of what I mean. As you can see the application has rendered the value that has been passed from the parent component, where I've used props.headertext. The second and third options both use JavaScript object de-structuring. The size of the props object may determine which way you choose here. You can de structure the props object in the argument bypassing the arrow function and object, with all the proper names supplied to the component. So for our component, this would look like this. 

The other option, is to pass in the props object and then de structure in the component function body. In either case, the advantage of this is that we can simply use the prop name and the component code now, which makes it more readable. Now I can remove, the props dot notation, and achieve the same result. You'll notice that React has given warnings that we've got some unused values. This is common in React, and it helps you to minimize the amount of code that it gets bundled that isn't used. Once I've got these values in the component, I can use them as part of the component logic. These props can now be used as expressions in the return to display data, including calling the function. I can also use values as part of the component logic. 

Here we show a map function to calculate the next number when we add one to the current number in the sum array prop, and create an array of JSX expressions to display it, in the components return. You'll notice there's a warning here on the console. Each child in a list should have a unique key prop. This is because React needs to be able to identify each component it renders. And when we constructed the array, we didn't let React know which component was which. 

So to fix this, I would add a key property to, each of the JSX expressions. In this instance, I'll use the sequence number. As I do that, it removes the warning. We can also loop through the keys and values in the object prop, to create an array of JSX expressions to display these. The logic to create the array is just JavaScript that poses a JSX expression, to an array. So that's how we can receive props inside a component, de structure them so we can easily use their names, and use the values either in component logic, or as part of a JSX expression, to display on our screen.

Lectures

• Static Versions
• React and Data
• What are Props and How Are They Passed?
• Default Props
• Prop Types