( a ? b : c ) 条件运算符, 当a为假值（0，null, undefined, ‘’, false）时 执行c, 反之执行b (a ?? b) 空置合并操作符，当 a 为 null 或者 undefined 时 返回 b , 反之为 a const num1 = 0const val1 = num1 ?? '122'const num2 = 1const val2 = num2

Up, up and away: house prices 涨不停：房价 Just as housing prices soar in Spain, attempts to contain them are growing ever more intense. 随着西班牙的房价高涨，为遏制房价做出的努力也越来越急切。 The government recently passed a