//建立测试数据
var ar = [];
for (var i = 0; i < 999999; i ++) ar.push(i.toString());

var dStart, dEnd, result = [];

//parseInt()方法
dStart = new Date();
for (var i = 0; i < ar.length; i ++) ar[i] = parseInt(ar[i]);
dEnd = new Date();
result.push(dEnd.getTime() - dStart.getTime());

//parseFloat()方法
dStart = new Date();
for (var i = 0; i < ar.length; i ++) ar[i] = parseFloat(ar[i]);
dEnd = new Date();
result.push(dEnd.getTime() - dStart.getTime());

//*1方法
dStart = new Date();
for (var i = 0; i < ar.length; i ++) ar[i] *= 1;
dEnd = new Date();
result.push(dEnd.getTime() - dStart.getTime());

document.write('<p>parseInt方法耗时：' + result[0] + 'ms<br />parseFloat方法耗时：' + result[1] + 'ms<br />乘1方法耗时：' + result[2] + 'ms');

------解决方案--------------------
var a='1234';
var z=(a-0)+1; //z=1235
这种方法比较简单


------解决方案--------------------
直接 parseInt(a,10) 吧

------解决方案--------------------
额

“123”-0+1  你试试把  这个简单把

------解决方案--------------------
parseInt