関数の使用方法 | UNIX & Linux コマンド・シェルスクリプト リファレンス
→ 関数名を指定したブロック内に処理を定義する。 関数名とその関数の処理を定義することで、一連の処理を関数を呼び出すことが可能になる。通常、関数の最後には return コマンドを指定し、その引数として与えた値が関数の終了ステータスとなる。 return コマンドの引数に指定できる値は、0 もしくは 1～255 の正の整数値のみである。マイナスの値も指定可能であるが、-1 を指定した場合は結果的に 255 になる。紛らわしいので、0 もしくは 1～255 の正の整数以外は指定しないようにする。 この return コマンドは省略可能で、省略された場合は関数内で最後に実行されたコマンドの終了ステータスが、関数自体の終了ステータスとなる。 関数を呼び出すときは、関数名と引数のリストを指定する。引数は省略可能である。呼び出すときの関数名は C言語などのように () を付ける必要はない。func(
Function: name - JavaScript | MDN
Standard built-in objectsFunctionConstructorFunction() constructorInstance methodsFunction.prototype.apply()Function.prototype.bind()Function.prototype.call()Function.prototype[Symbol.hasInstance]()Function.prototype.toString()Instance propertiesFunction.prototype.arguments Non-standard Deprecated Function.prototype.caller Non-standard Deprecated Function: displayName Non-standard Function: length
The names of functions in ES6
Update 2015-12-26: Sections for two caveats: “the name of a function is always assigned at creation” and “minification” The name property of a function contains its name: > function foo() {} > foo.name 'foo' This property is useful for debugging (its value shows up in stack traces) and some metaprogramming tasks (picking a function by name etc.). Prior to ECMAScript 6 (ES6), this property was alre
Inclusive Technology Consulting - Bocoup
If you’ve had any contact with JavaScript code, you’re probably very familiar with how to define and call functions, but are you aware of of how many different ways you can define a function? This is a common challenge of writing and maintaining tests in Test262—especially when a new feature comes into contact with any existing function syntax, or extends the function API. It is necessary to asser
Throttling function calls
If you've written any kind of validation on user input, like onkeypress then you'll know that sometimes you want to throttle the amount of times your function runs. A good example of this is Ajax based username validation - you don't want to hit the server on every key press, because most users will be able to write their name in around 1/10th of a second, so you should throttle the ajax request u
Check if a variable is of function type
Suppose I have any variable, which is defined as follows: var a = function() {/* Statements */}; I want a function which checks if the type of the variable is function-like. i.e. : function foo(v) {if (v is function type?) {/* do something */}}; foo(a); How can I check if the variable a is of type Function in the way defined above?
Paul O’Shannessy - Calling an Array of Functions in JavaScript
I’ve reviewed some bits of code over the past couple months that stored functions in an array and then at some point in the future needed to call all of them. This is a very simple thing to do, but something about the code always bothered me. Assuming: var callbacks = [ function() { console.log(1); }, function() { console.log(2); } ]; You end up iterating over the array and calling each function e
Every Possible Way to Define a Javascript Function
One small thing that confused me as I was learning JavaScript was the many different kinds of ways to define a JavaScript function. I could never seem to find one place that showed all of them, and explained why you might use each one. That is the aim of this post. So without further ado, here are ALL the ways to define a JavaScript function. Function Declarations: The "classic" declaration, which
Inclusive Technology Consulting - Bocoup
Every time I contribute to JSHint, I learn a little more about JavaScript. My most recent fantastical knowledge adventure led me to the behavior of the name attribute of function objects. JSHint has an interesting but lesser-known feature: code analysis reports. When used programatically, JSHint will return an object with some data about the code it has analyzed. This includes (but is not limited
ECMAScript 6 and Arrow Function · ariya.io
ECMAScript 6 and Arrow Function Feb 19, 2013 2 min read #es6 #javascript #web Experienced JavaScript programmers take advantage of function expressions, they are used a lot in callbacks, either for DOM access or any other related setup. Another syntax addition to the upcoming ECMAScript 6 is the arrow function expression to let us write a shorter function expression. A simple way to look at this a
Arrow Functions in JavaScript: Fat & Concise Syntax — SitePoint
Learn all about JavaScript arrow functions. We’ll show you how to use ES6 arrow syntax, and some of the common mistakes you need to be aware of when leveraging arrow functions in your code. You’ll see lots of examples that illustrate how they work. JavaScript arrow functions arrived with the release of ECMAScript 2015, also known as ES6. Because of their concise syntax and handling of the this key
Don’t Be Scared Of Functional Programming — Smashing Magazine
Stricter functional programming languages are typically used when a system’s performance and integrity are both critical — i.e. your program needs to do exactly what you expect every time and needs to operate in an environment where its tasks can be shared across hundreds or thousands of networked computers. These languages have a steep learning curve for most front-end web developers; however, ma
JavaScript Once Function
Every so often you have a function which you only want to run once. Oftentimes these functions are in the form of event listeners which may be difficult to manage. Of course if they were easy to manage, you'd just remove the listeners but that's a perfect world and sometimes you simply want the ability to only allow a function to be called once. Here's the JavaScript function to make that possi
Named function expressions demystified
Introduction Function expressions vs. Function declarations Function Statements Named function expressions Function names in debuggers JScript bugs JScript memory management Tests Safari bug SpiderMonkey peculiarity Solution Alternative solution WebKit's displayName Future considerations Credits Introduction Surprisingly, a topic of named function expressions doesn’t seem to be covered well enough
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【JavaScript】関数定義における4つの注意点 - みこむらめもむらむらむら
JavaScriptにおける関数の定義はシンプルだが 実際にコーディングに取り組んでみると 思わぬ不具合に悩まされることもある よくある誤りを避けるヒントを4つ紹介する はーいよろしくです return命令は途中で改行しない JavaScriptでは「基本的に」セミコロンで文末を認識する ただしセミコロンを省略した場合にも 適宜、前後の文脈から分の末尾を判断する つまりJavaScriptでは文末に セミコロンを付けることが好ましいが「必須ではない」 このような寛容さは 基本的にJavaScriptのハードルを下げる要因になるものだが 時として要らぬ混乱をもたらす原因にもなる var triangle = function(base, height) { return base * height / 2; } document.writeln('三角形の面積:' + triangle(5,
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