Mastering JavaScript Conditionals: Essential Guide for Beginners
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Chapter 1: Introduction to JavaScript Conditionals
Applications are designed to assist us in making decisions, and one of the most fundamental decision-making tools is the "if" condition. For instance, if the pizza delivery person shows up, you would open the door.
JavaScript, like many other programming languages, employs various conditional statements, such as "if." An "if" statement begins with a condition. If this condition is satisfied, the subsequent action will be executed.
if (pizzaArrives) {
openTheDoor();
}
In this example, if pizzaArrives evaluates to true, the function openTheDoor is invoked. Although including braces after the "if" statement is optional, it significantly improves readability and helps prevent bugs. Therefore, it’s advisable to always use them.
Section 1.1: Utilizing if/else Statements
There are scenarios where you might need to consider two distinct actions. In such cases, you can integrate an "else" statement alongside the "if." For example, when grilling hamburgers:
if (sideCooked) {
flipBurger();
} else {
keepCooking();
}
This conditional check could be programmed into a cooking robot at your favorite burger joint, although it may require additional code.
Subsection 1.1.1: Chaining Conditions with else if
If you need to evaluate multiple conditions, you can utilize "else if" as well:
if (sideCooked) {
flipBurger();
} else if (otherSideCooked) {
removeFromGrill();
} else {
keepCooking();
}
This structure allows for more elaborate checks. If even more conditions are required, you might find that a switch statement is more effective.
The first video, "JavaScript Conditionals #fullstackroadmap (Ep. 5.0)," offers insights into using conditionals in JavaScript and how to avoid common pitfalls.
Section 1.2: Understanding Conditional Operators
The operators utilized in "if" statements must yield either true or false. There are multiple options available for evaluation. Based on experience, it’s important to experiment with these to find the best fit.
if (9 > 5) { alert("Greater than"); } // greater than
if (5 < 8) { alert("Less than"); } // less than
if (9 >= 6) { alert("Greater than equal to"); } // greater than equal to
if (4 <= 6) { alert("Less than equal to"); } // less than equal to
if (4 != 6) { alert("Not equal to"); } // not equal to
Additionally, there are two logical operators to be aware of: Logical And (&&) and Logical Or (||). These operators are frequently used, but there's no need to feel intimidated.
const value1 = 4;
const value2 = -3;
console.log(value1 > 0 && value2 > 0); // Expected output: false
console.log(value1 > 0 || value2 > 0); // Expected output: true
The Logical And requires that both conditions be true for the entire expression to evaluate as true, while the Logical Or only needs one to be true.
Chapter 2: Mastering the Switch Statement
Switch statements evaluate an expression to determine which action to execute next. The execution continues until it encounters a break statement. Here is an example that determines the price of the desired shoes:
const shoes = 'Reebok';
switch (shoes) {
case 'Nike':
console.log('Nike shoes are $200.');
break;
case 'Adidas':
case 'Reebok':
console.log('Adidas and Reebok are $100 a pair.');
break;
default:
console.log(Sorry, we don't carry ${shoes}.);
}
This code will output "Adidas and Reebok are $100 a pair." It’s crucial to remember to include the break statement to avoid unintended behavior.
const shoes = 'Nike';
switch (shoes) {
case 'Nike':
console.log('Nike shoes are $200.');case 'Adidas':
case 'Reebok':
console.log('Adidas and Reebok are $100 a pair.');
break;
default:
console.log(Sorry, we don't carry ${shoes}.);
}
In this case, the absence of a break statement after the Nike case will result in the output of both "Nike shoes are $200." and "Adidas and Reebok are $100 a pair." This type of oversight is common among novice programmers, so don't be discouraged; you're not alone in this!
Conditionals are a cornerstone of JavaScript programming. Similar to other languages, they enable us to develop solutions efficiently. The use of if/else and switch statements is straightforward and user-friendly.
The second video, "7 Control Structures | Conditional Statements | Basics of JavaScript," delves deeper into the fundamental control structures in JavaScript, helping beginners grasp these concepts effectively.
Join me in exploring more about JavaScript conditionals!