深入理解JS中Number()，parseInt()，parseFloat()三者比较

　//JS区分0和-0
 var num = 123;
 var num = 123.123;
 var num = 0b10;
 var num = 010;
 var num = 0xff;
 var num = 5e2;
 var num = 5e-2;
 var num = NaN;
 console.log('值: ' , num);
 console.log('类型: ' , typeof(num))
 //NaN本身为false
 //其他类型转为数值失败时都为NaN
 console.log(NaN - 100);
 if(NaN){
  console.log('Yes');
 }else{
  console.log('No');
 }
 //NaN
 var a = '123ad';
 //123
 var a = '123';
 //NaN
 var a = 'f3ad';
 //0
 var a = false;
 //1
 var a = true;
 //NaN
 var a = undefined;
 var a = new Object();
 var a = Array(1,23);
 //1e+124
 var a = 10e123;
 //3
 var a = 0b11;
 //255
 var a = 0xff;
 //1.23
 var a = 1.23;
 //0
 var a = '';
 //1200
 var a = '12e2';
 //0
 var a = null;
 //90
 var a = 0132;
 var n = Number(a);
 console.log(n);

 //123
 var a = '123ad';
 //123
 var a = '123';
 //NaN
 var a = 'f3ad';
 //NaN
 var a = false;
 //NaN
 var a = true;
 //NaN
 var a = undefined;
 var a = new Object();
 //13 第一个值
 var a = Array(13,2);
 //3100000能够解析处时正常解析，不能时只返回第一个数字
 var a = 31e5;
 //3
 var a = 0b11;
 //255
 var a = 0xff;
 //1
 var a = 1.23;
 //NaN
 var a = '';
 //12 字符串只返回12e舍弃
 var a = '12e2';
 //NaN
 var a = null;
 //1
 var a = 1.5;
 //90
 var a = 0132;
 var n = parseInt(a);
 console.log(n);
 var a = parseInt("10",2);
 var a = parseInt("FF",16);
 var a = parseInt("10",8);
 console.log(a);

//123
 var a = '123ad';
 //123
 var a = '123';
 //NaN
 var a = 'f3ad';
 //NaN
 var a = false;
 //NaN
 var a = true;
 //NaN
 var a = undefined;
 var a = new Object();
 //13 第一个值
 var a = Array(13,2);
 //3100000 范围过大将转为科学计数法再大将为Infinity
 var a = 31e5;
 //3
 var a = 0b11;
 //255
 var a = 0xff;
 //1.23
 var a = 1.23;
 //NaN
 var a = '';
 //1200
 var a = '12e2aa';
 //NaN
 var a = null;
 //1.5
 var a = 1.5;
 //90
 var a = 0132;
 //
 var a = 1.113;
 var n = parseFloat(a);
 console.log(n);