functionouterFunction(outerVariable){functioninnerFunction(innerVariable){console.log('outerVariable:',outerVariable);console.log('innerVariable:',innerVariable);}returninnerFunction;}varnewFunction=outerFunction('outside');newFunction('inside');// 输出: outerVariable: outside innerVariable: inside 在这...
function outside() { const x = 5; function inside(x) { return x * 2; } return inside; } console.log(outside()(10)); // 20(而不是 10) 命名冲突发生在语句 return x * 2 上,inside 的参数 x 和outside 的变量 x 发生了冲突。这里的作用链域是 {inside、outside、全局对象}。因此 ...
functionmemoize(fn){constcache =newMap();returnfunction(...args){constkey =JSON.stringify(args);if(cache.has(key)) {returncache.get(key);}constresult = fn.apply(this, args);cache.set(key, result);returnresult;};} // Usageconstsl...
This function is going to return whatever you’re passing as its input; that is, if you’re passing 5, it’s going to return the value 5 (i.e., the function just acts as a mirror or identity). Note that our function operates only on the incoming argument i, and there is no glob...
bar: function (x) { return x % 2 != 0 ? 'yes' : 'no'; }(1) }; alert(foo.bar); // 'yes' As we see, foo.bar is a string but not a function as can seem at first inattentive glance. The function here is used only for initialization of the property — depending on the ...
function globalFD() { // 2) or inside the body // of another function function innerFD() {} } These are the only two positions in code where a function may be declared (i.e. it is impossible to declare it in an expression position or inside a code block). ...
toString = function () { console.log("数字对象"); return "改一下"; };const fooStr = `${foo}`;const numStr = `${num}`;console.log(numStr); // 改一下 Symbol Symbol 是原始值,并且是唯一的、不可变的。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 let sym = Symbol();...
A JavaScript function is executed when "something" invokes it (calls it). Example // Function to compute the product of p1 and p2 functionmyFunction(p1, p2) { returnp1 * p2; } Try it Yourself » JavaScript Function Syntax A JavaScript function is defined with thefunctionkeyword, followed...
the inputs the function will accept. These parameters are also referred to asarguments.“Return”...
A function can access all variables definedinsidethe function, like this: Example functionmyFunction() { vara =4; returna * a; } Try it Yourself » But a function can also access variables definedoutsidethe function, like this: Example ...