A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses (). Function names can contain letters, digits, underscores, and dollar signs (same rules as variables).

JavaScript functions are defined with the function keyword. You can use a function declaration or a function expression. Earlier in this tutorial, you learned that functions are declared with the following syntax: Declared functions are not executed immediately.

JavaScript 函数通过 function 关键词进行定义，其后是函数名和括号 ()。 函数名可包含字母、数字、下划线和美元符号（规则与变量名相同）。 圆括号可包括由逗号分隔的参数：

A function is a block of code which only runs when it is called. You can pass data, known as parameters, into a function. A function can return data as a result.

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2022年5月18日 · function functionname() { 执行代码 } 当调用该函数时，会执行函数内的代码。 可以在某事件发生时直接调用函数（比如当用户点击按钮时），并且可由 JavaScript 在任何位置进行调用。

The function statement declares a function. A declared function is "saved for later use", and will be executed later, when it is invoked (called). In JavaScript, functions are objects, and they have both properties and methods.

2025年3月22日 · In JavaScript, a function can be defined based on a condition. For example, the following function definition defines myFunc only if num equals 0: theObject.make = "Toyota"; }; } In addition to defining functions as described here, you can also use the Function constructor to create functions from a string at runtime, much like eval().

The most ordinary way of defining a function in JavaScript is by using the 'function' keyword, followed by a unique name for the function then, a list of parameters (that might or might not be empty), and a statement block bounded by curly braces.

2015年5月23日 · There are several workarounds to avoid using globals — we’ll go through them one by one now. Say you have three functions and a variable like this: function init(){...} function change(){...} function verify(){...} You can protect those from being overwritten by using an object literal: current:null, init:function(){...}, change:function(){...},