MDN \u7684\u89e3\u91cb<\/a>\uff0cfor…of \u7528\u4f86\u8dcc\u4ee3 iterable object \u4e2d\u7684 value\u3002<\/p>\n\n\n\nconst iterable = [3, 5, 7]\nfor (const i of iterable) {\n console.log(i) \n}\n\/\/ 3, 5, 7<\/code><\/pre>\n\n\n\n<\/span>3. \u4f7f\u7528\u6642\u6a5f<\/span><\/h2>\n\n\n\n<\/span>3.1 for…in \u7528\u5728 Object \u4e2d<\/span><\/h3>\n\n\n\nfor…in \u7528\u5728 Object \u4e2d\u53ef\u4ee5\u540c\u6642\u53d6\u51fa Object \u4e2d\u7684 key \u548c value\u3002<\/p>\n\n\n\n
const obj = {\n name: \"Jimmy\",\n age: 25,\n weight: \"75 kg\"\n}\nfor (const key in obj ) {\n console.log(key)\n console.log(obj[key])\n}\n\/\/ name, Jimmy, age, 25, weight, 75 kg<\/code><\/pre>\n\n\n\n<\/span>3.2 for…of \u7528\u5728 Object \u4e2d<\/span><\/h3>\n\n\n\nfor…of \u7528\u5728 Object \u4e2d\u4e5f\u53ef\u4ee5\u540c\u6642\u53d6\u51fa key \u548c value\uff0c\u548c for…in \u4e0d\u4e00\u6a23\u7684\u5730\u65b9\u662f\uff0c\u5fc5\u9808\u642d\u914d Object.keys \u65b9\u6cd5\u4f7f\u7528\uff0c\u5426\u5247\u6703\u51fa\u932f\u3002<\/p>\n\n\n\n
const obj = {\n name: \"Jimmy\",\n age: 25,\n weight: \"75 kg\"\n}\nfor (const key of Object.keys(obj)) {\n console.log(key)\n console.log(obj[key])\n}\n\/\/ name, Jimmy, age, 25, weight, 75 kg\nfor (const key of obj) {\n console.log(key)\n}\n\/\/ error!<\/code><\/pre>\n\n\n\n<\/span>3.3 for…in \u7528\u5728 Array \u4e2d<\/span><\/h3>\n\n\n\nfor…in \u7528\u5728 Array \u4e2d\u53ef\u4ee5\u540c\u6642\u53d6\u51fa Array \u4e2d\u7684 key \u548c value\u3002( Array \u7684 key \u662f index\u3002)<\/p>\n\n\n\n
const arr = [\"Jimmy\", 25, \"75 kg\"]\nfor (const key in arr ) {\n console.log(key)\n console.log(arr[key])\n}\n\/\/ 0, Jimmy, 1, 25, 2, 75 kg<\/code><\/pre>\n\n\n\n<\/span>3.4 for…of \u7528\u5728 Array \u4e2d<\/span><\/h3>\n\n\n\nfor…of \u7528\u5728 Array \u4e2d\u53ea\u80fd\u53d6\u51fa Array \u7684 value\u3002<\/p>\n\n\n\n
const arr = [\"Jimmy\", 25, \"75 kg\"]\nfor (const key of arr) {\n console.log(key)\n}\n\/\/ Jimmy, 25, 75 kg<\/code><\/pre>\n\n\n\n\n\n\u5982\u679c\u89ba\u5f97\u6211\u7684\u6587\u7ae0\u6709\u5e6b\u52a9\u7684\u8a71\uff0c\u6b61\u8fce\u5e6b\u6211\u7684\u7c89\u5c08\u6309\u8b9a\u54e6~\u8b1d\u8b1d\u4f60\uff01
<\/p>\n\n