JavaScript Cheat Sheet (DRAFT) by manongerard

JavaScript offers the class syntax that's very similar to languages like Java.

class Person {
    constructor(name) {
        this.name = name;
    }
    sayHello() {
    return 
Hello, I'm ${this.name}!
;
}
}
const p = new Person("Maria");
console.log(p.sayHello());

JavaScript objects can be thought of as collections of key-value pairs. They are hashes. They do not have fixed
shapes - properties can be added, deleted, re-ordered, mutated, or dynamically queried at any time. Objects keys are always strings or symbols.

const obj = {
    name: "Carrot",
    for: "Max",
    details: {
        color: "orange",
        size: 12,
    },
    fullDescr: function() {
       return this.name + " for " + this.for;
    }
};

Object properties can be accessed using dot ( . ) or square brackets ( [] ). e.g. obj.name or obj["name"]

- if and else
{{bb = 1}}
if (cdt) {
    code
} else if (cdt) {
    code
} else {
    code
}

- while
while (cdt) {
    code
}

- do ... while
do {
    code
} while (cdt);

- for loop
for (init; condition; update) {
    code
}

- for ... of
It iterates over iterables, most notably arrays,
for (const value of array) {
    code
}

- for ... in
It visits all enumerable properties of an object.
for (const property in object) {
    code
}

- switch
switch(variable/expression) {
    case value1:  
        // body of case 1
        break;
    case value2:  
        // body of case 2
        break;
    case valueN:
        // body of case N
        break;
    default:
        // body of default
}
break works like in C/Java. If you don't add a break statement, execution will "fall through" to the next level.
Comparison using ===, cases can be any expression

- throw
Errors can be thrown using the throw statement.
throw new Error(string);

- try ... catch
try {
   code;
} catch (e) {
    console.error(string, e);
}
There's no conditional catch in JavaScript — if you only want to handle one type of error, you need to catch everything, identify the type of error using instanceof, and then rethrow the other cases.
try {
   code;
} catch (e) {
   if (e instanceof RangeError) {
      code
} else {
   throw e;
   }
}

- return

- continue