Question

我正在阅读一个文本文件，并在我的反应项目中使用正则表达式将其转换为JSON格式。它工作正常但不包括文本文件的最后20-30行。将其转换为JSON时存在一些问题，但我无法理解这个问题。

这是我的代码：

    readTextFile = file => {
        let rawFile = new XMLHttpRequest();
        rawFile.open("GET", file, false);
        rawFile.onreadystatechange = () => {
            if (rawFile.readyState === 4) {
                if (rawFile.status === 200 || rawFile.status === 0) {
                    let allText = rawFile.responseText;
                    // console.log(allText)

                    let reg = /\d\d\d\d-(0?[1-9]|1[0-2])-(0?[1-9]|[12][0-9]|3[01]) (00|[0-9]|1[0-9]|2[0-3]):([0-9]|[0-5][0-9]):([0-9]|[0-5][0-9])/g;

                    let arr = [];
                    let start = null;
                    let line, lastSpacePos;
                    let match;
                    while ((match = reg.exec(allText)) != null) {
                        if(start) {
                            line = allText.slice(start, match.index).trim();
                            lastSpacePos = line.lastIndexOf(' ');
                            arr.push({
                                date: line.slice(0, 19),
                                text: line.slice(20, lastSpacePos).trim(),
                                user_id: line.slice(lastSpacePos).trim()
                            });
                        }

                        start = match.index
                    }
                    console.log(arr);

                    this.setState({
                        // text: JSON.stringify(arr)
                        text: allText
                    });
                }
            }
        };

Answer 1

我不确定问题中现有代码的问题。

要使用替代方法获得问题中描述的预期结果，您可以使用RegExp /\s{2,}|\n+/g替换大于2的空格字符和换行符号; /[\d-]+\s[\d:]+/g获取日期; /.+(?=\s\w+\s$|\s\w+$)|\w+\s$|\w+$/g匹配空格，字符和空格字符后面的文本或字符串和字符的结尾，然后是空格字符，后跟字符和空格字符或字符串结尾;从.map()

返回一个具有为数组中每个元素设置的属性的对象

let allText = `2014-06-01 23:07:58 President Resigns in Georgia’s Breakaway Region of 
Abkhazia t.co/DAploRvCvV                                                    nytimes 
2014-06-01 23:48:06 The NYT FlipBoard guide to understanding climate 
change and its consequences t.co/uPGTuYiSmQ                                 nytimes 
2014-06-01 23:59:06 For all the struggles that young college grads 
face, a four-year degree has probably never been more valuable 
t.co/Gjf6wrwMsS         nytimes 
2014-06-01 23:35:09 It's better to be a community-college graduate than 
a college dropout t.co/k3CO7ClmIG                                           nytimes 
2014-06-01 22:47:04 Share your experience with Veterans Affairs health 
care t.co/PrDhLC20Bt                                                        nytimes 
2014-06-01 22:03:27 Abandon Hope, Almost All Ye Who Enter the N.B.A. 
Playoffs t.co/IQAJ5XNddR                                                    nytimes`;

// replace more than one consecutive space character and new line characters
allText = allText.replace(/\s{2,}|\n+/g, " ");
// get dates
let dates = allText.match(/[\d-]+\s[\d:]+/g);
// get characters that are not dates
// spread `dates` to resulting array
// return object
let res = allText
.split(/[\d-]+\s[\d:]+\s/)
.filter(Boolean)
.map((text, index) => 
  [dates[index], ...text.match(/.+(?=\s\w+\s$|\s\w+$)|\w+\s$|\w+$/g)])
.map(([date, text, user_id]) => ({date, text, user_id}));

console.log(res);

文本文件为JSON，最后几行不包含在结果中

1 个答案: