使用 Array#reduce
方法
var res = data.reduce(function(obj, v) { // increment or set the property // `(obj[v.status] || 0)` returns the property value if defined // or 0 ( since `undefined` is a falsy value obj[v.status] = (obj[v.status] || 0) + 1; // return the updated object return obj; // set the initial value as an object}, {})var data = [{ "id": "65:0", "status": "ORANGE"}, { "id": "65:0", "status": "GREEN"}, { "id": "65:0", "status": "ORANGE"}, { "id": "65:0", "status": "YELLOW"}, { "id": "65:0", "status": "RED"}, { "id": "65:0", "status": "GREEN"}, { "id": "65:0", "status": "GREEN"}, { "id": "65:0", "status": "ORANGE"}, { "id": "65:0", "status": "YELLOW"}, { "id": "65:0", "status": "GREEN"}];var res = data.reduce(function(obj, v) { obj[v.status] = (obj[v.status] || 0) + 1; return obj;}, {})console.log(res);虽然可以使用 Array#forEach
具有相同代码的方法。
var res = {};data.forEach(function(v) { res[v.status] = (res[v.status] || 0) + 1;})var data = [{ "id": "65:0", "status": "ORANGE"}, { "id": "65:0", "status": "GREEN"}, { "id": "65:0", "status": "ORANGE"}, { "id": "65:0", "status": "YELLOW"}, { "id": "65:0", "status": "RED"}, { "id": "65:0", "status": "GREEN"}, { "id": "65:0", "status": "GREEN"}, { "id": "65:0", "status": "ORANGE"}, { "id": "65:0", "status": "YELLOW"}, { "id": "65:0", "status": "GREEN"}];var res = {};data.forEach(function(v) { res[v.status] = (res[v.status] || 0) + 1;})console.log(res);
