if (typeof object.methodName === 'function') { console.log('方法存在'); } else { console.log('方法不存在'); } 4. 尝试调用方法并捕获异常 通过尝试调用该方法并捕获可能抛出的异常来判断方法是否存在。 代码语言:txt 复制 try { if (object.methodName) { ...
Callback function to execute once path is verified passing a boolean parameter value to the function as its argument. const fs = require('fs'); const path = './my-awesome-file.txt'; fs.exists(path, function (doesExist) { if (doesExist) { console.log('file exists'); } else { cons...
How to check if a file exists in the filesystem using Node.js, using the `fs` moduleThe way to check if a file exists in the filesystem, using Node.js, is by using the fs.existsSync() method:const fs = require('fs') const path = './file.txt' try { if (fs.existsSync(path)...
bucket:'yourBucketName', });asyncfunctionbucketisExist() {try{// 指定存储空间名称。constresult =awaitclient.getBucketInfo('Yourbucketname')console.log('bucketInfo: ', result.bucket) }catch(error) {// 判断指定的存储空间是否存在。if(error.name==='NoSuchBucketError') {console.log('Bucket ...
first exists true exists after unlink src false // symlink still exists, why is it false?? The issue arises because I want to create a symlink if it doesn't exist, or unlink it and re-create it if it does. Currently I'm using fs.exists to perform this check, but ran into this ...
if(typeof yourfunctionname === 'function'){ //存在且是function } else{ //不存在或不是function } 或者 typeof
Check if a Collection Exists in MongoDB Using NodeJS To find if a collection exists, we first need to connect with the MongoDB server, and then we need to query like this: dbs.collection("Your_collection_name").find().toArray(function(err, res) { if ( res.length > 0 ) { console...
[373dbb0e6c] -doc: mark--env-file-if-existsflag as experimental (Juan José)#56893 [d436888cc8] -doc: fix typo in cjs example ofutil.styleText(Deokjin Kim)#56769 [91638eeb4a] -doc: clarify sqlite user-defined function behaviour (René)#56786 ...
minify({"file1.js": "var a = function() {};"}, { sourceMap: { root: "http://example.com/src", url: "out.js.map" } }); If you're compressing compiled JavaScript and have a source map for it, you can use sourceMap.content: var result = UglifyJS.minify({"compiled.js": "...
bucket: 'yourBucketName', }); async function bucketisExist() { try { // 指定存储空间名称。 const result = await client.getBucketInfo('Yourbucketname') console.log('bucketInfo: ', result.bucket) } catch (error) { // 判断指定的存储空间是否存在。 if (error.name === 'NoSuchBucketError...