convert string into array of integers

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刺人心
刺人心 2020-11-30 19:32

I want to convert the following string \'14 2\' into an array of two integers. How can I do it ?

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  • 2020-11-30 20:03

    An alternative to Tushar Gupta answer would be :

    '14 2'.split(' ').map(x=>+x);
    
    // [14, 2]`
    

    In code golf you save 1 character. Here the "+" is "unary plus" operator, works like parseInt.

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  • 2020-11-30 20:03

    First split the string on spaces:

    var result = '14 2'.split(' ');
    

    Then convert the result array of strings into integers:

    for (var i in result) {
        result[i] = parseInt(result[i], 10);
    }
    
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  • 2020-11-30 20:05

    Just for fun I thought I'd throw a forEach(f()) solution in too.

    var a=[];
    "14 2".split(" ").forEach(function(e){a.push(parseInt(e,10))});
    
    // a = [14,2]
    
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  • 2020-11-30 20:07

    The point against parseInt-approach:

    There's no need to use lambdas and/or give radix parameter to parseInt, just use parseFloat or Number instead.


    Reasons:

    1. 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
      
    2. It's shorter.

    3. 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'! >_<
      

    Notice: In Firefox parseInt works about 4 times faster, but still slower than others. In total: +e < Number < parseFloat < parseInt

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  • 2020-11-30 20:08

    us the split function:

    var splitresult = "14 2".split(" ");
    
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