mhrooz
d9bba74979
add a [Symbol.Iterable] to make the object iterable so that the object can use for of loop the [Symbol.Iterable] is a function, it should return a object includesdone and value Array.from method can return Array.from a arraylike object and iterable object string can be used in array.from as well
56 lines
909 B
JavaScript
56 lines
909 B
JavaScript
let range = {
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from: 1,
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to: 5
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}
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range[Symbol.iterator] = function(){
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return {
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current: this.from,
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last: this.to,
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next(){
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if(this.current <= this.last){
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return {done: false, value: this.current++};
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} else {
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return {done: true};
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}
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}
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}
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};
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for(let num of range){
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console.log(num);
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}
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for(let ch of "tests"){
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console.log(ch)
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}
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let arrayLike = {
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0: "Hello",
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1: "World",
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length: 2
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};
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// Array.from
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let arr = Array.from(arrayLike);
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console.log(arr.pop()); // World
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arr = Array.from(range);
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console.log(arr); //1, 2, 3, 4, 5
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arr = Array.from(range, num => num * num);
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console.log(arr); //1, 4, 9, 16, 25
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let s = "split";
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let split_s = s.split('');
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let arr_s = Array.from(s);
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console.log(split_s);
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console.log(split_s[0]);
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console.log(split_s[1]);
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console.log(split_s.length);
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console.log(arr_s);
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console.log(arr_s[0]);
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console.log(arr_s[1]);
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console.log(arr_s.length);
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