table of Contents
1. Function Classification
1. No function reference function name () {
Function body
}
function print(){
for(var i=0;i<10;i++){
document.write("hello world! <br/>");
}
}2. Reference function
function print(n){
for(var i=0;i<n;i++){
document.write("hello world! <br/>");
}
}
print(5);2. Built-in functions: alert () ······
3. custom function: function named identifier
4.arguments array
function sum(){
for(var i=0;i<arguments.length;i++){
sum += arguments[i];
}
alert(sum);
}
sum(3,4,5,6);2. Return Values
function add(num1,num2){
return num1+num2;
}
var result=add(3,4);
alert(result);3. Scope
var a=10;
function sum(){
var a=5;
alert(a);
}
alert(a);//10
sum();//5
alert(a);//104. recursive
-
Interview be used, but the work is generally prohibited, such as sum (100) = sum (99) +100;
function sum(n){
if(n==1){
return 1;
}
return sum(n-1)+n;
}
alert(sum(100));The event-driven functions
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