Declaration A prototype for a function which takes a function parameter looks like the following: void func ( void (*f)(int) ); This states that the parameter f will be a pointer to a function which has a void return type and which takes a single int parameter. The following function (print) is an example of … Read more
Bind creates a new function that will force the this inside the function to be the parameter passed to bind(). Here’s an example that shows how to use bind to pass a member method around that has the correct this: var myButton = { content: ‘OK’, click() { console.log(this.content + ‘ clicked’); } }; myButton.click(); … Read more
You just need to remove the parenthesis: addContact(entityId, refreshContactList); This then passes the function without executing it first. Here is an example: function addContact(id, refreshCallback) { refreshCallback(); // You can also pass arguments if you need to // refreshCallback(id); } function refreshContactList() { alert(‘Hello World’); } addContact(1, refreshContactList);
The $@ variable expands to all command-line parameters separated by spaces. Here is an example. abc “$@” When using $@, you should (almost) always put it in double-quotes to avoid misparsing of arguments containing spaces or wildcards (see below). This works for multiple arguments. It is also portable to all POSIX-compliant shells. It is also … Read more
Your logic fails if optionalArg is passed, but evaluates as false – try this as an alternative if (typeof optionalArg === ‘undefined’) { optionalArg = ‘default’; } Or an alternative idiom: optionalArg = (typeof optionalArg === ‘undefined’) ? ‘default’ : optionalArg; Use whichever idiom communicates the intent best to you!
It forces the parser to treat the part following the + as an expression. This is usually used for functions that are invoked immediately, e.g.: +function() { console.log(“Foo!”); }(); Without the + there, if the parser is in a state where it’s expecting a statement (which can be an expression or several non-expression statements), the … Read more
A lambda is just an anonymous function – a function defined with no name. In some languages, such as Scheme, they are equivalent to named functions. In fact, the function definition is re-written as binding a lambda to a variable internally. In other languages, like Python, there are some (rather needless) distinctions between them, but … Read more
Use .bind() when you want that function to later be called with a certain context, useful in events. Use .call() or .apply() when you want to invoke the function immediately, and modify the context. Call/apply call the function immediately, whereas bind returns a function that, when later executed, will have the correct context set for … Read more
See Python PEP 8: Function and Variable Names: Function names should be lowercase, with words separated by underscores as necessary to improve readability. Variable names follow the same convention as function names. mixedCase is allowed only in contexts where that’s already the prevailing style (e.g. threading.py), to retain backwards compatibility.
Are you talking about lambda expressions? Like lambda x: x**2 + 2*x – 5 Those things are actually quite useful. Python supports a style of programming called functional programming where you can pass functions to other functions to do stuff. Example: mult3 = filter(lambda x: x % 3 == 0, [1, 2, 3, 4, 5, … Read more