JS便捷技巧

1.  JSON.stringify濾除null的屬性

let baz = {
	a : 1,
	f:null,
	x:'ddd',
	b : { c : 2,d:null,e:'null' }
};

// 過濾null的值
let replacer = function (key, value) {
	return value != null ? value: undefined;
};
console.log(JSON.stringify(baz, replacer))

2.  兩個對象賦值

let arra = {
    'aaa':'',
    'bbb':'',
    'ccc':''
}
let arrb = {
    'aaa':'111',
    'bbb':'222',
    'ccc':'333',
    'ddd':'444',
    'eee':'555'
}
listAssign(arra,arrb)
const listAssign = (arrA, arrB) => Object.keys(arrA).forEach(key => { arrA[key] = arrB[key] || arrA[key]});
listAssign(arra ,arrb )