NodeJS 阻塞/非阻塞

var fs = require(‘fs‘);
var data = fs.readFileSync(‘test.txt‘)
console.log(data.toString());
console.log(‘----------------‘);

var fs = require(‘fs‘);
fs.readFile(‘test.txt‘, function(error, data) {
    if (error) {
        console.log(error);
        return;
    } else {
        console.log(data.toString());
    }
})

console.log(‘----------------‘);