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What are Props and how are they passed?

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Application and Service Development with ReactJS
course-steps 9 certification 5 lab-steps 3
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Overview
DifficultyBeginner
Duration14m
Students10

Description

This module looks at more complex data structures, building on what was covered in the intermediate data structures module.

Learning Objectives 

The objectives of this module are to provide you with an understanding of: 

  • How to construct a factor in R  
  • How to construct a data frame in R  
  • How to modify a data frame  
  • How to subset a data frame
  • Data frames automatically factorising data in R  

Intended Audience 

Aimed at all who wish to learn the R programming language. 

Prerequisites 

No prior knowledge of R is assumed.

Delegates should already be familiar with basic programming concepts such as variables, scope, and functions.

Experience of another scripting language such as Python or Perl would be an advantage.

Understanding mathematical concepts will be beneficial.

Feedback 

We welcome all feedback and suggestions - please contact us at qa.elearningadmin@qa.com to let us know what you think.

Transcript

- [Instructor] What are props and how are the passed? According to the documentation, props are a way of passing data from parent to child. Props create a one-way communication channel for data that allows it flow from the top or parent component to the bottom or child components. An important concept to understand, is that once the value of props is set, they are immutable within the component. The only way to change the props values in a component is to get it re-rendered by a parent with the new values for props. Components get their props from this point of render. You can see here that the component called componentWithProps, is being given a prop called headerText, that has a value of header text from header text prop. This value will be available inside the componentWithProps component and can be used in any display logic or as part of the return mark up. The value supplied as a prop need not be primitive data like a string, it can be any type of data, included objects, arrays and functions. You can supply them as JavaScript expressions inside curly braces to do this. You can see examples of these in the code. Just so you know, I could've chosen any name for a prop, it's good practice to call them something useful.

About the Author

Students662
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Courses10
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An outstanding trainer in software development with more than 15 years experience as a Corporate and Apprentice Trainer, ICT Teacher and Head of Department, with a passion for technology and its uses. Continuing to develop existing and new skills and courses, primarily in web design using PHP, JavaScript, HTML, CSS and SQL but also OOP (Java), programming foundations (Using Python), DevOps (Git, CI/CD, etc) and Agile/Scrum. Practically minded, a quick learner and a problem solver with an attention to detail to ensure high quality outcomes.