js: Know a value in json data to get other values

var wtfl1economicsLengthData=data.questionOne //json数据
$(wtfl1economicsLengthData).each(function () {
    
    
			if(this.pid==20){
    
    //已知值进行判断
				var key = this.key;
                cosole.log(key);
			}  
});