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function arguments

2022-07-29 19:34:00 【A Shan classmate.】

函数的参数

基础

函数是可以带参数的

函数：The most basic packaging method,The purpose is to reuse methods

封装：Pack some loose pieces together to form a whole

复用：重复使用

Functions can be written in various ways depending on the number of formal parameters

For example, encapsulate a method that returns hours, minutes and seconds

<body>
  <!-- 函数是可以带参数的 -->
  <!-- 函数：The most basic purpose of encapsulation is to reuse methods -->
  <script> // Get the current date and print it function showData(){
       var now =new Date(); var hour=now.getHours(); var minute=now.getMinutes(); var second=now.getSeconds(); return `${
        hour}:${
        minute}:${
        second}` } //The call prints the return value console.log(showData()); </script>
</body>

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具体情况如上：Put a whole bunch of code in {}里面,形成一个整体,然后起一个名字,Then call it by the function name{}里面的代码

Functions can take parameters

单参数

** 制作一个abs函数,返回参数的绝对值**

<script> // 制作一个abs函数,返回参数的绝对值 // 如果》0Just return a positive numbernum本生 // 如果>0It's a negative numbernumbecomes positive and returns function abs(x){
       if(x > 0) return x; if(x < 0){
       return x*=-1 } return num>0 ? x : -num; } console.log(abs(-90)); </script>

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多参数

制作一个abs函数,Returns the sum between the two

    <script>; // --------分割-------- // // Multiple parameters are separated by commas function add(x,y){
       return x + y; } add(1,2) </script>

函数的arguments

arguments：函数中隐式自带的变量,When the stored function is called,parameter received

适合场景：Cooperate to implement those parameters whose incoming length is not fixed
Create a function that adds all the arguments passed in

function add() {
    
  var min = 0;
  for (i = 0; i < arguments.length; i++) {
    
    min += arguments[i];
  }
  return min;
}
console.log(add(1, 2, 3, 4));
console.log(add(1, 2, 3, 4, 5, 6, 7, 8));
console.log(add(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12));