It was changed between 3.1 and 3.2: This is a terse description of the new features added to bash-3.2 since the release of bash-3.1. Quoting the string argument to the [[ command’s =~ operator now forces string matching, as with the other pattern-matching operators. So use it without the quotes thus: i=”test” if [[ $i … Read more
As a general rule: you pretty much never need the ternary operator in Ruby. The reason why you need it in C, is because in C if is a statement, so if you want to return a value you have to use the ternary operator, which is an expression. In Ruby, everything is an expression, … Read more
Remove the course_enrollment_settings.base_price immediately after CASE: SELECT CASE WHEN course_enrollment_settings.base_price = 0 THEN 1 … END CASE has two different forms, as detailed in the manual. Here, you want the second form since you’re using search conditions.
Change the first false by true. I know it seems stupid to have (true || true) but it proves your point. bool result = true || true && false; // –> true result = (true || true) && false; // –> false result = true || (true && false); // –> true
There are many approaches to this. If you use Ruby 2.3 or above, you can use dig my_hash.dig(‘key1’, ‘key2’, ‘key3’) Plenty of folks stick to plain ruby and chain the && guard tests. You could use stdlib Hash#fetch too: my_hash.fetch(‘key1’, {}).fetch(‘key2’, {}).fetch(‘key3′, nil) Some like chaining ActiveSupport’s #try method. my_hash.try(:[], ‘key1’).try(:[], ‘key2’).try(:[], ‘key3’) Others use … Read more
If you’re looking for a one-liner to do that, you can pull the ?: operation out of the string interpolation and concatenate with + instead: let fileExists = false // for example println(“something ” + (fileExists ? “exists” : “does not exist”)) Outputs: something does not exist
If your requirement was simply empty or null (like mine when I saw this title in a search result), you can use Dart’s safe navigation operator to make it a bit more terse: if (routeinfo[“no_route”]?.isEmpty ?? true) { // } Where isEmpty checks for an empty String, but if routeinfo is null you can’t call … Read more
Twig example: {% if array.key is defined %} // do something {% else %} // do something else {% endif %}
You can use the define plugin. I use it by doing something as simple as this in your webpack build file where env is the path to a file that exports an object of settings: // Webpack build config plugins: [ new webpack.DefinePlugin({ ENV: require(path.join(__dirname, ‘./path-to-env-files/’, env)) }) ] // Settings file located at `path-to-env-files/dev.js` … Read more
If your DBMS does not impose limitations on which table you select from when you execute an insert, try: INSERT INTO x_table(instance, user, item) SELECT 919191, 123, 456 FROM dual WHERE NOT EXISTS (SELECT * FROM x_table WHERE user = 123 AND item = 456) In this, dual is a table with one row only … Read more