No error , No gain

This question's answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. What is the most efficient way to clone a JavaScript object? I've seen obj = eval(uneval(o)); being used, but that's non-standard and only supported by Firefox. I've done things like obj = JSON.parse(JSON.stringify(o)); but question the efficiency..

This question's answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. Usually I would expect a String.contains() method, but there doesn't seem to be one. What is a reasonable way to check for this? ECMAScript 6 introduced String.prototype.includes: const string = "foo"; const substring = "oo"; console.log(string.in..

How do I check whether a file exists or not, without using the try statement? If the reason you're checking is so you can do something like if file_exists: open_it(), it's safer to use a try around the attempt to open it. Checking and then opening risks the file being deleted or moved or something between when you check and when you try to open it. If you're not planning to open the file immedia..

I've been messing around with JSON for some time, just pushing it out as text and it hasn't hurt anybody (that I know of), but I'd like to start doing things properly. I have seen so many purported "standards" for the JSON content type: application/json application/x-javascript text/javascript text/x-javascript text/x-json But which one is correct, or best? I gather that there are security and b..

How do you call an external command (as if I'd typed it at the Unix shell or Windows command prompt) from within a Python script? Use the subprocess module in the standard library: import subprocess subprocess.run(["ls", "-l"]) The advantage of subprocess.run over os.system is that it is more flexible (you can get the stdout, stderr, the "real" status code, better error handling, etc...). Even t..

I always thought Java uses pass-by-reference. However, I've seen a blog post that claims that Java uses pass-by-value. I don't think I understand the distinction they're making. What is the explanation? Java is always pass-by-value. Unfortunately, when we deal with objects we are really dealing with object-handles called references which are passed-by-value as well. This terminology and semantic..

This question's answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. How would you explain JavaScript closures to someone with a knowledge of the concepts they consist of (for example functions, variables and the like), but does not understand closures themselves? I have seen the Scheme example given on Wikipedia, ..

질문자 :Satch3000 JavaScript에서 현재 연도를 어떻게 얻습니까? new Date() 객체를 만들고 getFullYear() 호출합니다. new Date().getFullYear() // returns the current year 항상 현재 연도를 표시하는 바닥글과 같은 몇 가지 기본 예제 컨텍스트를 제공하기 위해 허용된 답변을 가로채기: © 위의 HTML이 로드된 후 실행되는 다른 위치: document.getElementById("year").innerHTML = new Date().getFullYear(); footer { text-align: center; font-family: sans-serif; } © 2018 by FooBar Jason Harwig // Return tod..

질문자 :mrblah 로컬 브랜치와 원격 브랜치 diff 은 어떻게 볼 수 있습니까? git diff / 예를 들어, git diff main origin/main 또는 git diff featureA origin/next 물론 말했다 원격 추적 브랜치 중 당신은 할 필요가 git fetch 첫째; 원격 저장소의 분기에 대한 최신 정보가 필요합니다. Jakub Narębski 원격 추적 분기를 업데이트하려면 git fetch 를 입력한 다음 다음을 입력해야 합니다. git diff git branch -a 모든 분기(로컬 및 원격)를 나열한 다음 목록에서 분기 이름을 선택할 수 있습니다(원격 분기 이름에서 remotes/ 예: git diff main origin/main (여기서 "main"은 로컬 메..

질문자 :Ashkan Kh. Nazary PHPLint , JSLint , 그리고 저는 최근 에 일부 IDE 에 대한 내용을 읽는 동안 "즉석에서 JS 코드를 린트할 수 있습니다"를 발견했습니다. 그래서, 무엇을 "linting"는 무엇입니까? Linting은 잠재적인 오류에 대해 코드를 분석하는 프로그램을 실행하는 프로세스입니다. Wikipedia에서 Lint 를 참조하십시오. lint는 원래 C 언어 소스 코드에서 일부 의심스럽고 이식 불가능한 구조(버그일 가능성이 있음)에 플래그를 지정하는 특정 프로그램에 부여된 이름입니다. 이 용어는 이제 모든 컴퓨터 언어로 작성된 소프트웨어에서 의심스러운 사용을 표시하는 도구에 일반적으로 적용됩니다. Oded Lint는 C 코드를 통해 컴파일, 링크 및 실행하기..