ES6 Note

String

1. unicode can use {} in most chinese character

2. support iterate use fo of loop

for (let i of 'PHP is best language!') {
  console.log(i);
}

3. String.repeat() (ES6)

repeat

4. String.padStart() & String.padEnd() (ES8 Living Standard)

padStart
padEnd

Number

1. Number.isFinite()
   test this number whether is finite

2. Number.isNaN()
   test this number whether is not a Number

3. a ** b
   Exponentiation

Math

1. Math.trunc()
   return Integer

2. Math.sign()
   judge a Number is postive or negative
   if(positive) return +1
   if(nagative) return -1
   if(zero) return 0
   if(NaN) return NaN

Function

1. default value

function log(x, y = 'World') {
  console.log(x, y);
}

Array

1. Array.find() & findIndex() (ES6)

find
findIndex

2. Array.pop()
   Delete last element, return this element, modify origin Array.

3. Array.push()
   Add a element behind last element in Array, return Array length, modify origin Array.

4. Array.reverse()
   reverse Array, return new Array.

5. Array.shift()
   Delete first element, return this element, modify origin Array.

6. Array.sort()
   Sort by Unicode, return Array.

var items = [
  { name: 'Edward', value: 21 },
  { name: 'Sharpe', value: 37 },
  { name: 'And', value: 45 },
  { name: 'The', value: -12 },
  { name: 'Magnetic' },
  { name: 'Zeros', value: 37 }
];

items.sort(function (a, b) {
  if (a.value > b.value) {
    return 1;
  }
  if (a.value < b.value) {
    return -1;
  }
  // a 必须等于 b
  return 0;
});

7. Array.splice(start, deleteCount, item1, item2, ...)
   From index start, delete some elements, after add some elements.
   return delete element Array or empty Array.

8. Array.unshift()
   Add a element in the front of Array, return the new Array length.