Intro to JavaScript
# Intro to JavaScript
1. Which keywords are used to declare a variable in JavaScript?
Var, Let, Const
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2. What is the definition of a function?
A block of code designed to perform a particular task.
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3. What are the SOLID principles?
Single Responsibility
Open Closed
Liskov Substitution
Interface Segregation
Dependency Inversion
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4. Given this array:
let fruit = ['apple', 'banana', 'pineapple', 'orange', 'strawberry']
What index is the pineapple's current position? How do you know?
2. Arrays start at 0,1,2,3....
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5. With these two objects:
let you = { name:"You", hair: true, friends: [] }
let them = { name:"Them", hair: false, friends: [] }
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how would you .push the them object into the you object's array of friends?
them.push(name)
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6. Give an example of a JavaScript Conditional:
if(taco < 2){
console.log("tacos")
}else{
console.log("taco")
}
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7. In the for loop below, what is the name of the piece belongs inside the empty "______" space? What would you put here to increase i by one on every iteration?
for ( let i = 0; i < arr.length; _______ ) {
//...
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Increment
i++
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8. What does the DOM acronym stand for? Which file is first accessed to render the DOM?
Document Object Model. HTML Text is read first.
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9. What are the 9 ECMAScript types as defined by MDN?
Primative Values: Boolean Type, Null Type, Undefined Type, Number Type, BigInt Type, String Type, Symbol Type
Objects
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10. When it comes to functions or methods, what is the difference between a parameter and an argument?
Parameters are the names created when defining a function. Arguments are the values that the functions receives from the parameters when the function is invoked.
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11. What is the difference between a primitive value and a reference value?
Primitive Values are data that are stored on the stack. References values are objects that are stored in the heap.
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