๐ฐfunction expression
an expression that evaluates to a function object.
JS โฉ value โฉ function โฉ expression
an expression that evaluates to a function as value.
// โญโโโ ๐ธ function expression โโโโฎ
const area = function (w, h) { return w * h };different forms of F.E.
features of F.E.
roles of function expression๏ผ
as variable ( ๐ more about๏ผfunction expression as variable)
as method
only function expression can be anonymous function.
( ๐ function name scope)
the name (identifier) of a "function expression" is in its own function name scope, nested between the outer enclosing scope and the inner function scope.
๐function*
โญarrow function is a function expression.
replit๏ผfunction expression
// โญโโโ ๐ธ function expression โโโโฎ
const area = function (w, h) { return w * h }; // โญ๏ธ 1. as "variable"
const math = { // โญ๏ธ 2. as "method"
// ๐ธ "named" function expression
// โคทโญโโโโโโโโโโโโโโโฎ <-------- ๐ธ function name: "f" (local)
factorial: function f(n) { // available only in function body.
// ...
}
};
// โญโโ ๐ธ FE โโโฎ
( function(){ } )(); // โญ๏ธ 3. as "IIFE" (form 1)
// โญโโโ ๐ธ FE โโโฎ
!function(){ }(); // โญ๏ธ 3. as "IIFE" (form 2)
// โญโโโ ๐ธ FE โโโโโฎ
f('click', function (e) { } ); // โญ๏ธ 4. as "callback"Last updated
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