Question

从结果数组 javascript 中获取值

2017-02-12

85

javascript

Array[7998]
[0 … 99]
0:"        1    2015-01-14 13:27:07 1   0   2   0"
1:"        1    2015-01-14 13:30:11 1   0   2   0"
2:"        1    2015-01-14 13:33:34 1   0   2   0"
3:"        1    2015-01-14 13:33:43 1   0   2   0"
4:"        2    2015-01-21 10:54:37 1   0   1   0"
5:"        2    2015-02-03 11:39:57 1   0   1   0"
6:"        2    2015-02-03 11:44:56 1   4   1   0"
7:"        1    2015-02-03 11:44:59 1   4   2   0"
8:"        2    2015-02-03 11:49:49 1   0   1   0"
9:"      221    2015-02-03 11:49:51 1   0   1   0"
10:"      221   2015-02-03 11:49:53 1   0   1   0"
11:"      221   2015-02-03 11:52:07 1   0   1   0"
12:"        1   2015-02-26 17:29:24 1   4   2   0"

嗨！我从这段代码中得到了这个结果：

function onReadFile(file){
  var txt = file.target.result;
  var list = txt.split('\n');
//  var result = list.map(function(item){
//     return item.split('\n');
//  });
  console.log(list);
}

有没有办法只获取前三个值或列？前三列代表 ID、日期和时间，所以我只需要提取这三个，就像这样..

[1,2015-01-14,13:27:07][1,2015-01-14,13:30:11][1,2015-01-14,13:33:34][...]

谢谢。

Answer 1

var text = "   1    2015-01-14 13:30:11 1   0   2   0\n        1    2015-01-14 13:33:34 1   0   2   0\n        1    2015-01-14 13:33:43 1   0   2   0";

var list = 
text.split('\n')                 // split the lines
    .map(function(line) {        // map the lines
      var parts = line.trim()    // trim the current line (remove surrounding spaces)
                  .split(/\s+/); // split the cols by multiple spaces (space, tabs, ...)

      return parts.slice(0, 3);  // return an array like your desired output (just the first three cols of each row)
      
      // IF YOU WANT THE RESULT TO BE AN OBJECT THEN REMOVE THE ABOVE RETURN STATEMENT AND UNCOMMENT THE CODE BELLOW

      //var o = {};
      //o.id = parts[0];
      //o.date = parts[1];
      //o.time = parts[2];

      //return o;
    });

console.log(list);

Answer 2

您可以使用正则表达式将字符串拆分为多个空格。

var fields = list.split(/\s+/);
console.log(fields);

前三列分别位于索引 1、2 和 3。

Answer 3

.match() 个不是空格的字符， .slice() 结果数组的前三个元素

var list = ["        1    2015-01-14 13:27:07 1   0   2   0"
,"        1    2015-01-14 13:30:11 1   0   2   0"
,"        1    2015-01-14 13:33:34 1   0   2   0"
,"        1    2015-01-14 13:33:43 1   0   2   0"
,"        2    2015-01-21 10:54:37 1   0   1   0"
,"        2    2015-02-03 11:39:57 1   0   1   0"
,"        2    2015-02-03 11:44:56 1   4   1   0"
,"        1    2015-02-03 11:44:59 1   4   2   0"
,"        2    2015-02-03 11:49:49 1   0   1   0"
,"      221    2015-02-03 11:49:51 1   0   1   0"
,"      221   2015-02-03 11:49:53 1   0   1   0"
,"      221   2015-02-03 11:52:07 1   0   1   0"
,"        1   2015-02-26 17:29:24 1   4   2   0"];

var result = list.map(function(text) {
                   return text.match(/[^\s]+/g).slice(0, 3)
                 });

console.log(result);