Introduction to JavaScript – Control Flow: if/else Statements

Introduction to JavaScript – Control Flow: if/else Statements

The core task of programming is writing lists of instructions for computers, or translating our ideas from human-speak to computer-speak.

Let’s learn how we can ask JavaScript to think like us and make decisions the way we do.

We’ll start with human-speak. Many decisions we make everyday boil down to this sentence in some form:

“If something is true, let’s do option 1, or else, if it is false, let’s do option 2.”

This sentence looks fairly similar when we write it with JavaScript. See for yourself:

let needsCoffee = true;
if (needsCoffee === true) {
console.log('Finding coffee');
} else {
console.log('Keep on keeping on!');

1) Lines of code between curly braces are called blocks. if/else statements have two code blocks. If the variable needsCoffee is true, the program will run the first block of code. Otherwise, it will run the other block of code.

2) needsCoffee is the condition we are checking inside the if‘s parentheses. Since it is equal to true, our program will run the code between the first opening curly brace { (line 2) and the first closing curly brace } (line 4). It will ignore the else { … } part. In this case, we’d see Finding coffee log to the console.

3) If needsCoffee were false, only the console.log() statement in the else block would be executed.

if/else statements are how programs can process yes/no questions programmatically.

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About the Author: Bernard Aybout

In the land of bytes and bits, a father of three sits, With a heart for tech and coding kits, in IT he never quits. At Magna's door, he took his stance, in Canada's wide expanse, At Karmax Heavy Stamping - Cosma's dance, he gave his career a chance. With a passion deep for teaching code, to the young minds he showed, The path where digital seeds are sowed, in critical thinking mode. But alas, not all was bright and fair, at Magna's lair, oh despair, Harassment, intimidation, a chilling air, made the workplace hard to bear. Management's maze and morale's dip, made our hero's spirit flip, In a demoralizing grip, his well-being began to slip. So he bid adieu to Magna's scene, from the division not so serene, Yet in tech, his interest keen, continues to inspire and convene.