有没有原生的替代方案可以从以下内容开始:
const colorArray = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'];
to:
Object {
"red": 3,
"green": 2,
"blue": 1,
"purple": 1,
"black": 1
}
在JavaScript中?
const colorArray = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'];
function categorizeUnique(array) {
const distinct_objects = {};
const length = array.length;
for(let i=0; i<length; i++) {
const distinct_objects_keys = Object.keys(distinct_objects);
const possible_index = distinct_objects_keys.indexOf(array[i]);
if(possible_index === -1) {
distinct_objects[array[i]] = 1;
} else {
distinct_objects[distinct_objects_keys[possible_index]]++;
}
}
return distinct_objects;
}
const result = categorizeUnique(colorArray);
console.log(result);
That was my try to accomplish this but I'd like a native solution already built in. 感谢您宝贵的时间和努力!
acc[color]||0
被解释为当前颜色的累加器:如果前者是“未定义”(在第一次越过每个特定颜色时),则它将被解释为0
。(acc[color]=(acc[color]||0)+1, acc)
实际上与acc[color] = acc[color]||0+1; return acc
相同。 - Yevhen Horbunkov逗号运算符
->
无序列规则。 - Ele