我有下面的字符串

var a = "1,2,3,4";

当我…

var b = a.split(',');

我得到b为["1","2","3","4"]

我能做点什么让b等于[1,2,3,4]吗?


当前回答

没有必要使用lambdas和/或给parseInt的基数参数,只需使用parseFloat或Number代替。

原因:

It's working: var src = "1,2,5,4,3"; var ids = src.split(',').map(parseFloat); // [1, 2, 5, 4, 3] var obj = {1: ..., 3: ..., 4: ..., 7: ...}; var keys= Object.keys(obj); // ["1", "3", "4", "7"] var ids = keys.map(parseFloat); // [1, 3, 4, 7] var arr = ["1", 5, "7", 11]; var ints= arr.map(parseFloat); // [1, 5, 7, 11] ints[1] === "5" // false ints[1] === 5 // true ints[2] === "7" // false ints[2] === 7 // true It's shorter. It's a tiny bit quickier and takes advantage of cache, when parseInt-approach - doesn't: // execution time measure function // keep it simple, yeah? > var f = (function (arr, c, n, m) { var i,t,m,s=n(); for(i=0;i++<c;)t=arr.map(m); return n()-s }).bind(null, "2,4,6,8,0,9,7,5,3,1".split(','), 1000000, Date.now); > f(Number) // first launch, just warming-up cache > 3971 // nice =) > f(Number) > 3964 // still the same > f(function(e){return+e}) > 5132 // yup, just little bit slower > f(function(e){return+e}) > 5112 // second run... and ok. > f(parseFloat) > 3727 // little bit quicker than .map(Number) > f(parseFloat) > 3737 // all ok > f(function(e){return parseInt(e,10)}) > 21852 // awww, how adorable... > f(function(e){return parseInt(e)}) > 22928 // maybe, without '10'?.. nope. > f(function(e){return parseInt(e)}) > 22769 // second run... and nothing changes. > f(Number) > 3873 // and again > f(parseFloat) > 3583 // and again > f(function(e){return+e}) > 4967 // and again > f(function(e){return parseInt(e,10)}) > 21649 // dammit 'parseInt'! >_<

注意:在Firefox中,parseInt的工作速度大约快4倍,但仍然比其他的慢。总共:+e < Number < parseFloat < parseInt

其他回答

下划线js的方式-

var a = "1,2,3,4",
  b = a.split(',');

//remove falsy/empty values from array after split
b = _.compact(b);
//then Convert array of string values into Integer
b = _.map(b, Number);

console.log('Log String to Int conversion @b =', b);

你可以使用数组。映射将每个元素转换为一个数字。

var a = "1,2,3,4";

var b = a.split(',').map(function(item) {
    return parseInt(item, 10);
});

检查文档


或者像User: thg435所指出的那样更优雅

var b = a.split(',').map(Number);

Number()将完成其余的工作:检查这里


注意:对于不支持map的旧浏览器,你可以自己添加一个实现:

Array.prototype.map = Array.prototype.map || function(_x) {
    for(var o=[], i=0; i<this.length; i++) { 
        o[i] = _x(this[i]); 
    }
    return o;
};

如果您需要将字符串数组转换为数字,这将非常有效。

const numbers = arr => arr.map(Number);
numbers(['1', '2', '3','4']);     // [1, 2, 3, 4]
let ar = [ '682',    '874',    '906',    '11168',  '73714',
  '74377',  '74034',  '138860', '138891', '139161', '139562',
  '139733', '139560', '74049',  '139759', '139934', '140104',
  '141335', '141356', '141334', '141337', '141360', '141358',
  '141365', '141419', '143333', '151477', '147342', '141355',
  '167847', '192141', '196760', '191687', '197351', '197055',
  '198852', '198731', '198816', '199034', '200053', '199226',
  '217818', '200055', '222039', '230533', '230530', '231127',
  '222042', '231100', '236171', '236913', '236980', '237015',
  '237016', '237052', '237551', '237560', '237590', '237637',
  '237733', '237731', '237655', '238890', '238910', '238837',
  '238926', '238972', '238925', '239755', '239696', '239898',
  '240037', '239909', '240036', '240082', '240097', '240526',
  '240770', '678151', '678950', '678985'];
let arry=[]
ar.map(arr=>{
arry.push(parseInt(arr))
});

console.log(arry);

Array.from()详情请访问MDN

let a = "1,2,3,4";
let b = Array.from(a.split(','),Number);

or

let c = ["1", "2", "3", "4"].map(Number);

B和c是一个数字数组。

演示:

设a = "1,2,3,4"; let b = Array.from(a.s split(','),Number); let c = ["1", "2", "3", "4"].map(Number); Console.log (' b: ${b}, c: ${c} ');