js中Number()方法

Number方法（整体转换0）:

var a = "+100";alert( a+100 ); // "100100"alert(Number(a)); // 100 var a1="000100";alert(Number(a1));//100var a2 = "";alert( Number(a1) ); // 0var a3 = "  ";alert( Number(a1) ); // 0var a4 = []; //[""]  [123]  ["123"] [1,2,3]alert( Number(a4) ); // 0  0  123  123  NaNvar a5 = null;alert( Number(a5) ); // 0var a6；alert( Number(a6) ); // NaNvar a7=function(){alert(0)};alert( Number(a7) ); // NaNvar json={abc:123}alert( Number(json) ); // NaN