当new Array数组长度为2或以上,结果都是NaN;
为空,0或1时,结果都是0.
console.log(+new Array(200));//NaN
console.log(+new Array());//0
console.log(+new Array(1));//0
当new Array数组长度为2或以上,结果都是NaN;
为空,0或1时,结果都是0.
console.log(+new Array(200));//NaN
console.log(+new Array());//0
console.log(+new Array(1));//0