二维数组变一维数组

• 利用apply实现

let arr1 = [[{ name: '哈哈', age: 1 }], [{ name: '嘻嘻', age: 2 }], [{ name: '嘿嘿', age: 3 }]];
let arr2 = [].concat.apply([], arr1)
// arr2: [{name: '哈哈', age: 1},{name: '嘻嘻', age: 2},{name: '嘿嘿', age: 3}]

• 利用es5的arr.reduce()实现

let arr1 =[[{ name: '哈哈', age: 1 }], [{ name: '嘻嘻', age: 2 }], [{ name: '嘿嘿', age: 3 }]];
let arr2 = arr1.reduce((a, b){return a.concat(b) }
// arr2: [{name: '哈哈', age: 1},{name: '嘻嘻', age: 2},{name: '嘿嘿', age: 3}]

• 利用es6实现

let arr1 = [[{ name: '哈哈', age: 1 }], [{ name: '嘻嘻', age: 2 }], [{ name: '嘿嘿', age: 3 }]];
function flatten(arr) {
  return [].concat(...arr.map(x => (Array.isArray(x) ? flatten(x) : x)));
}
let arr2 = flatten(arr1)
// arr2: [{name: '哈哈', age: 1},{name: '嘻嘻', age: 2},{name: '嘿嘿', age: 3}]

• 利用 Array.prototype.flat() 实现

let arr1 = [[{ name: '哈哈', age: 1 }], [{ name: '嘻嘻', age: 2 }], [1, { name: '嘿嘿', age: 3 }]];
let arr2 =arr1.flat()
// arr2: [{name: '哈哈', age: 1},{name: '嘻嘻', age: 2},1,{name: '嘿嘿', age: 3}]

原文作者 https://www.cnblogs.com/EnSnail/p/9762764.html