node. JS synchronous and asynchronous read Write delete file 1

node. js Beginner, the process of synchronizing and asynchronously reading a document in a file:

1, synchronous reading:

var fs=require ("FS")

Read the document directly and assign a value to the variable by synchronizing the return value

var data=fs.readfilesync ("Input.txt");

Console.log (Data.tostring ());

2, asynchronous read:

var fs=require ("FS");

Returns the data value obtained by the callback function;

Fs.readfile ("Input.txt", function (Err,data) {

Console.log (Data.tostring ());

})

3. Asynchronous write:

var fs=require ("FS");
var data= "There's a big thing happening today!" "
Fs.writefile ("02.txt", data,function (Err) {
if (err) {
throw err;
}else{
Console.log ("File Write succeeded! ")
}
})

4. Delete files:

var fs=require ("FS");

Fs.unlink ("02.txt", function (Err) {
if (err) {
throw err;
}else{
Console.log ("Delete succeeded! ")
}
})

node. JS synchronous and asynchronous read Write delete file 1