Subset of Javascript that is recommended to commit to memory by all new programmers

JS_Subset_Cheatsheet.md

Be able to write out these skeletons in less than five seconds. It is vital that these are committed to memory and you don't need to think about it when asked to create these.

1. Defining a function

var aFunc = function(arg1, arg2) {
  // your code in function body here using arg1 and arg2
}

1. Iterating over an array

for (var i = 0; i < array.length; i++) {
  // your code in loop body here using array[i]
}

1. Looping from 0-10

for (var i = 0; i < 10; i++) {
  // your code here using i
}

1. Looping over an object

for (key in object) {
  // your code here using key
}

1. If statement

if(truthyStatement) {
  // do something here
} else if (someOtherTruthyStatement) {
  // otherwise do stuff in this block
} else {
  // otherwise default to do stuff in this block
}

1. Array access

var myArray = [];
myArray.push('hello');
myArray.push(10);
console.log(myArray[0]);
console.log(myArray[1]);

1. Object access

var myObject = {};
myObject['name'] = 'MyName';
console.log(myObject.name);

var myVar = 'age'
myObject[myVar] = 100;
console.log(myObject.age);

Methods to know about. You should be able to know what each of these does and quickly navigate documents to get the exact syntax.

• Strings
  1. charAt()
  2. concat()
  3. contains()
  4. indexOf()
  5. length()
  6. search()
  7. splice()
  8. split()
  9. sub()
  10. substr()
  11. toLowerCase()
  12. toUpperCase()
• Arrays
  1. join()
  2. length()
  3. pop()
  4. push()
  5. reverse()
  6. shift()
  7. unshift()
  8. slice()
  9. splice()
• Objects
  1. Object.keys()

Be able to write out these skeletons in less than five seconds. It is vital that these are committed to memory and you don't need to think about it when asked to create these.

1. Defining a function

var aFunc = function(arg1, arg2) {
  // your code in function body here using arg1 and arg2
}

1. Iterating over an array

for (var i = 0; i < array.length; i++) {
  // your code in loop body here using array[i]
}

1. Looping from 0-10

for (var i = 0; i < 10; i++) {
  // your code here using i
}

1. Looping over an object

for (key in object) {
  // your code here using key
}

1. If statement

if(truthyStatement) {
  // do something here
} else if (someOtherTruthyStatement) {
  // otherwise do stuff in this block
} else {
  // otherwise default to do stuff in this block
}

1. Array access

var myArray = [];
myArray.push('hello');
myArray.push(10);
console.log(myArray[0]);
console.log(myArray[1]);

1. Object access

var myObject = {};
myObject['name'] = 'MyName';
console.log(myObject.name);

var myVar = 'age'
myObject[myVar] = 100;
console.log(myObject.age);

Methods to know about. You should be able to know what each of these does and quickly navigate documents to get the exact syntax.

• Strings
  1. charAt()
  2. concat()
  3. contains()
  4. indexOf()
  5. length()
  6. search()
  7. splice()
  8. split()
  9. sub()
  10. substr()
  11. toLowerCase()
  12. toUpperCase()
• Arrays
  1. join()
  2. length()
  3. pop()
  4. push()
  5. reverse()
  6. shift()
  7. unshift()
  8. slice()
  9. splice()
• Objects
  1. Object.keys()