大约有 16,000 项符合查询结果（耗时：0.0303秒） [XML]
CSS background image alt attribute
This is one I have not had to tackle before. I need to use alt tags on all images in a site including those used by CSS background-image attribute.
...
What is the difference between Scala's case class and class?
I searched in Google to find the differences between a case class and a class . Everyone mentions that when you want to do pattern matching on the class, use case class. Otherwise use classes and also mentioning some extra perks like equals and hash code overriding. But are these the only reasons...
How to open a specific port such as 9090 in Google Compute Engine
I have 2 Google Compute Engine instances and I want to open port 9090 in both the instances. I think we need to add some firewall rules.
...
React JSX: selecting “selected” on selected option
...t component for a <select> menu, I need to set the selected attribute on the option that reflects the application state.
...
Truncating floats in Python
I want to remove digits from a float to have a fixed number of digits after the dot, like:
29 Answers
...
Is there a timeout for idle PostgreSQL connections?
I see a lot of them. We are trying to fix our connection leak. But meanwhile, we want to set a timeout for these idle connections, maybe max to 5 minute.
...
What is the purpose of willSet and didSet in Swift?
...nt seems to be that sometimes, you need a property that has automatic storage and some behavior, for instance to notify other objects that the property just changed. When all you have is get/set, you need another field to hold the value. With willSet and didSet, you can take action when the value is...
this.setState isn't merging states as I would expect
...
var newSelected = _.extend({}, this.state.selected);
newSelected.name = 'Barfoo';
this.setState({ selected: newSelected });
I've used function _.extend() function (from underscore.js library) here to prevent modification to the existing selected part of the state by creating a shallow copy of it...
Create new tmux session from inside a tmux session
I'm writing a shell script that creates / attaches or switches to a given session, depending on whether one is inside tmux and the session exists.
...
How can I list ALL DNS records?
...
When you query for ANY you will get a list of all records at that level but not below.
# try this
dig google.com any
This may return A records, TXT records, NS records, MX records, etc if the domain name is exactly "google.com". However, it will not retu...