Resolve promises one after another (i.e. in sequence)?
问题 Consider the following code that reads an array of files in a serial/sequential manner. readFiles returns a promise, which is resolved only once all files have been read in sequence. var readFile = function(file) { ... // Returns a promise. }; var readFiles = function(files) { return new Promise((resolve, reject) => var readSequential = function(index) { if (index >= files.length) { resolve(); } else { readFile(files[index]).then(function() { readSequential(index + 1); }).catch(reject); } };