Example analysis of arguments usage in Javascript_javascript skills

The examples in this article describe the usage of arguments in Javascript. Share it with everyone for your reference. The specific analysis is as follows:

Let’s first look at the following example:

function add(n1,n2){ 
  return n1+n2; 
} 
function add(n1,n2,n3) { 
  return n1+n2+n3; 
} 
alert(add(1,2));
//NaN，js中调用方法采用就近原则；
//而由于该方法没有传入n3，所以结果是NaN

There is no method overloading in js. How to solve the above problem?

//arguments 
function f1(){ 
var sum=0; 
for(var i=0;i<arguments.length;i++){ 
sum+=arguments[i]; 
} 
return sum; 
} 
alert(f1(1,2,3,4,5));
//利用arguments，计算例子加上数字的和 
function ff(name){ 
var sum=0; 
for(var i=1;i<arguments.length;i++){ 
sum+=arguments[i]; 
} 
return arguments[0]+sum; 
} 
alert(ff('例子',1,2,3,4,5));//例子15 
//姓名，年龄 
function test(name,age) { 
if(!age){//age未传参时，age为undefined 
age=18; 
} 
alert('名字是'+name+'年龄是'+age); 
} 
test('小明');//名字是小明年龄是18

I hope this article will be helpful to everyone’s JavaScript programming design.