从javascript向变量调用文本文件时筛选行号
我得到了这段代码,它将把File.txt的所有内容调用到变量fileContent中。如何使它只获得一个指定的行号而不是整个文件内容从javascript向变量调用文本文件时筛选行号,javascript,Javascript,我得到了这段代码,它将把File.txt的所有内容调用到变量fileContent中。如何使它只获得一个指定的行号而不是整个文件内容 var xhr = new XMLHttpRequest(); xhr.open("GET","data/File.txt",false); xhr.send(null); var fileContent = xhr.responseText; 按换行符拆分文件并获取所需的行号: const lineNumber = 42; const myLine = fil
var xhr = new XMLHttpRequest();
xhr.open("GET","data/File.txt",false);
xhr.send(null);
var fileContent = xhr.responseText;
按换行符拆分文件并获取所需的行号:
const lineNumber = 42;
const myLine = fileContent.split('\n')[lineNumber];
或者使其更易于重用:
const getLine = (content, lineNumber) => content.split('\n')[lineNumber];
getLine(fileContent, 42);
您可以执行错误处理。按换行符拆分文件,并获取所需的行号:
const lineNumber = 42;
const myLine = fileContent.split('\n')[lineNumber];
或者使其更易于重用:
const getLine = (content, lineNumber) => content.split('\n')[lineNumber];
getLine(fileContent, 42);
您可以执行错误处理。您可以按行尾字符拆分响应文本
// fileContent now constain an array of strings
// where every item is a line
var fileContent = xhr.responseText.split('\n');
var lineNumber = 0;
var lineContent = fileContent[lineNumber]; // the content of the first line
// total number of lines
var linesCount = fileContent.length;
// random integer between 0 (minimum index) and linesCount - 1 (maximum index)
var randomLineNumber = Math.floor(Math.random() * linesCount);
var randomLineContent = fileContent[randomLineNumber];
可以按行尾字符拆分响应文本
// fileContent now constain an array of strings
// where every item is a line
var fileContent = xhr.responseText.split('\n');
var lineNumber = 0;
var lineContent = fileContent[lineNumber]; // the content of the first line
// total number of lines
var linesCount = fileContent.length;
// random integer between 0 (minimum index) and linesCount - 1 (maximum index)
var randomLineNumber = Math.floor(Math.random() * linesCount);
var randomLineContent = fileContent[randomLineNumber];
有没有办法数一数有多少条线,然后取一条随机线?有没有办法数一数有多少条线,然后取一条随机线?