Question

我编写了一个用于读取文件内容的代码，而我运行它时不会返回文件内容而是NAN。以下是我的代码： -

var fs = require('fs');

if (fs.existsSync('Temp')){
console.log('Directory exists, removing...');
if(fs.existsSync('Temp/new.txt')){
    fs.unlinkSync('Temp/new.txt');
}
fs.rmdirSync('Temp');
}

fs.mkdirSync('Temp');

console.log('running');

if(fs.existsSync('Temp')){
process.chdir('Temp');
fs.writeFileSync('test.txt', 'This is some test text for the file2');
fs.renameSync('test.txt', 'new.txt');
console.log('File has size:', + fs.statSync('new.txt').size + ' bytes');
console.log('File contents:', + fs.readFileSync('new.txt', {encoding: 'utf8'}));
}

Answer 1

您正在使用unary operator将任何内容转换为数字而不是连接输出。

您要么从您的,中删除逗号（console.log）并使用字符串连接，要么删除+并将内容作为console.log第二个参数发送。< / p>

// I'm concatenating here
console.log('File contents:' + fs.readFileSync('new.txt', {encoding: 'utf8'}));
// I'm sending the content as second argument of console.log
console.log('File contents:', fs.readFileSync('new.txt', {encoding: 'utf8'}));

您正在做的事情可以转换为此内容，除非NaN内容为数字，否则会返回new.txt。

console.log(
    'File contents:', 
    Number(fs.readFileSync('new.txt', {encoding: 'utf8'}))
);

console.log('File content: ', + 'new.txt content'); // NaN
console.log('File content: ', Number('new.txt content')); // NaN

console.log('File content: ', 'new.txt content'); // ok
console.log('File content: ' + 'new.txt content'); // ok

NodeJs readfilesync返回NAN而不是文件内容

1 个答案: