JavaScript之检测数组或对象是否存在空值toLowerCasecallslicesplitstringifyindexOfprototypetoString

Posted 2022-09-14 web半晨

class IsType 
	constructor(type) 
		type = type || '';
		this.type = type.toLowerCase();
	
	checkType(obj) 
		let val = Object.prototype.toString.call(obj);
		val = val.slice(1, val.length - 1);
		val = val.split(' ')[1];
		val = val.toLowerCase();
		return val === this.type;
	
	matchString(obj) 
		let toStr = JSON.stringify(obj);
		return toStr.indexOf('') !== -1 || toStr.indexOf('[]') !== -1;
	
	rationality(obj) 
		if (this.checkType(obj) && !this.matchString(obj) && Object.keys(obj).length > 0) 
			return true;
		 else if (this.checkType(obj) && !this.matchString(obj) && obj.length > 0) 
			return true;
		 else 
			return false;
		
	


let a = new IsType('Array'),
o = new IsType('object');

console.log(a.rationality());
// false
console.log(a.rationality([7]));
// true
console.log(a.rationality([7, []]));
// false
console.log(o.rationality( id: 2, list: [6], l: [9] ));
// true
console.log(o.rationality( id: 2, list: [6], l: [] ));
// false