将每个数组项的出现次数和 return 结果作为一个对象进行计数
Count each array item occurrence and return result as an object
任何原生替代品来自:
const colorArray = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'];
至:
Object {
"red": 3,
"green": 2,
"blue": 1,
"purple": 1,
"black": 1
}
在 javascript??
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);
这是我尝试实现的,但我想要一个已经内置的本机解决方案。
感谢您付出宝贵的努力和时间!!
Array.prototype.reduce()
似乎与您要查找的内容非常接近:
const src = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'],
result = src.reduce((acc,color) => (acc[color]=(acc[color]||0)+1, acc), {})
console.log(result)
.as-console-wrapper{min-height:100%;}
使用.reduce
:
const colorArray = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'];
let colorCount = colorArray.reduce((a, c) => ({ ...a, [c]: a[c] + 1 || 1}), {} );
console.log(colorCount);
任何原生替代品来自:
const colorArray = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'];
至:
Object {
"red": 3,
"green": 2,
"blue": 1,
"purple": 1,
"black": 1
}
在 javascript??
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);
感谢您付出宝贵的努力和时间!!
Array.prototype.reduce()
似乎与您要查找的内容非常接近:
const src = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'],
result = src.reduce((acc,color) => (acc[color]=(acc[color]||0)+1, acc), {})
console.log(result)
.as-console-wrapper{min-height:100%;}
使用.reduce
:
const colorArray = ['red', 'green', 'green', 'blue', 'purple', 'red', 'red', 'black'];
let colorCount = colorArray.reduce((a, c) => ({ ...a, [c]: a[c] + 1 || 1}), {} );
console.log(colorCount);