1. Deconstruct assignment
1.1 Destruct assignment of arrays
In short, deconstructed assignment is to match the exact pattern of = left and right, which is lazy, and the corresponding right-hand side is used if there is a value, no value is the default or undefined(the last example below).
1.2 Object deconstruction assignment
1.3 String Deconstruction assignment
In fact, string deconstruction assignments are exactly the same as arrays
1.4 Application scenarios of deconstructing assignment
Array traversal in ES5
2.1 the for
2.2 the forEach
ForEach does not support the break continue keyword
2.3 the map
Map returns the new array, but does not change the original array
2.4 the filter
Filter returns the new array, but does not alter the original array to filter out elements that do not meet the criteria
2.5 some
The return value of some is Boolean and returns true as long as there is one qualifying element
2.6 every
The return value is a Boolean that returns true if all elements satisfy the condition
2.7 recude
2.8 for the in
For in iterates through the array, so we should not use for in to iterate through the array
ES6 array traversal mode
3.1 the find
Returns the first element that matches, or undefined if it does not
3.2 findIndex
Returns the index of the first element that meets the criteria