JS学习笔记——分支与循环

if判断

var age=3;
if(age>3){
        alert("haha");
}else if(age<5){
        alert("kuwa");
}else{
        alert("kuwa");
}

while循环，避免程序死循环

while(age<100){
    age=age+1;
    console.log(age)
}

for循环

for(let i = 0;i<100;i++){
    console.log(i)
}

forEach循环

var age=[12,3,12,3,12,3,12,31,23,123];

//函数
age.forEach(funcition(value){
        console.log(value)
}

for...in

//for(var index in object){}

for (var num in age){
    if(age.hasOwnProperty(num){
        console.log("存在")
        console.log(age[num])
    
        }
}