javaScript把其它类型转换为Number类型

console.log(Number("12.5")); //12.5
console.log(Number("12.5px")); //NAN
console.log(Number("12.5.5px"));//NAN
console.log(Number(""));//0

console.log(Number(true));//1
console.log(Number(false));//0
console.log(isNaN(false));//false 是有效数字

console.log(Number(null));//0
console.log(Number(undefined));//NaN

console.log(Number({num:"10"}));//NaN
console.log(Number({}));//NaN ({num:"10"}).toString();是"[object Object]" 是非有效数字字符所以是NaN
console.log(Number([]));//0 [].toString()是""所以转为数字是0
console.log(Number([12]));//12 [12].toString()是"12"所以转为数字是12
console.log(Number([12,23]));//NaN [12].toString()是"12,23"里面的","是非有效数字字符所以是NaN

let a=10+null+true+[]+undefined+'腾讯'+null+[]+10+false;
console.log(a)//11undefined腾讯null10false