what"s the difference between operands such as Array.prototype.slice.call (arrary,args) and arrays calling slice methods directly in javascript
what"s the difference between operands such as Array.prototype.slice.call (arrary,args) and arrays calling slice methods directly in javascript
array calls the slice method directly so that returns a shallow copy of a selected array from start to end (excluding the end) to a new array object.
you can use Array.prototype.slice.call (arguments) to convert Array-like objects / collections into a new array.
or abbreviated to [] .slice.call (arguments)
in addition, the new API Array.from in ES6 can also transform class array objects into real arrays
in practical applications, class array objects are often NodeList collections returned by DOM operations and arguments of functions
for example:
let arrayLike = {
'0': 'a',
'1': 'b',
'2': 'c',
length: 3
}
// es5
var arr = Array.prototype.slice.call(arrayLike) // ["a", "b", "c"]
var arr = [].slice.call(arrayLike) // ["a", "b", "c"]
// es6
let arr2 = Array.from(arrayLike) // ["a", "b", "c"]args belongs to the class array object, which is similar to the content obtained by document.getElementsByClassName. It only has the array structure but does not have the prototype method of the array, so it will need to execute the slice method of binding data in the form of Array.prototype.slice.call.
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