md`## Sorting Arrays
\`Array.sort()\` is a deadly sort. Also it sors elements alphabetically, so to sort numbers, pass a callback function
`
numbers = [11,2,3,4,5,6,7,8]
numbers.sort()
numbers.sort((a1, a2) => a1 - a2)
testreduce = [10, 2, -30, 4, 55, 6, 7, 8]
testreduce.reduce((x, y) => x > y ? x : y)
md`### Sum array elements`
testreduce.reduce((x, y) => x + y)
md`### Find number in array greater than a given number`
testreduce2 = [10, 2, -30, 4, 550, 6, 7, 8]
testreduce2.reduce((x, y) => x > y ? x : y, 100)
objectInArray = [{x: 1,y: 2,z: 3}]
primitiveArray = [1,2,3,5,6]
destinationFromDestructuring = [...primitiveArray, 700]
destinationFromDestructuring[0] = 100
primitiveArray
objectInArrayDestructuring = [...objectInArray]
objectInArrayDestructuring[0].x = 5
JSON.stringify(objectInArrayDestructuring)
JSON.stringify(objectInArray)
md`### Primitives array deep copy using \`Array.slice()\``
sourceForSlicing = [...primitiveArray]
destinationFromSlice = sourceForSlicing.slice()
destinationFromSlice[0] = 100
sourceForSlicing
md`### Object in array not deep copied using Array.slice()`
objectInArraysSliceCopy = objectInArray.slice()
objectInArraysSliceCopy[0].x = 5
JSON.stringify(objectInArray)
JSON.stringify(objectInArraysSliceCopy)
sourceObj = ({a: {b: 5}})
sourceObjWithArray = ({a: {b: [1,2,3]}})
destinationObj = ({...sourceObj})
destinationObj.a.b = 50
JSON.stringify(sourceObj)
JSON.stringify(destinationObj)
destinationObjWithArray = ({...sourceObjWithArray})
destinationObjWithArray.a.b.push(4)
JSON.stringify(sourceObjWithArray)
JSON.stringify(destinationObjWithArray)
md`## \`in\` operator
### Check for object property
`
car = ({make: 'Honda', model: 'Accord', year: 1998})
'make' in car
md`### Check for index in array`
lengthFour = [1,2,3,4]
`${4}` in lengthFour
`${3}` in lengthFour
md`## \`Set\` data structure
### Find unique letters in a string
`
temp = new Set('abcaacb')
[...temp]
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