ES 之 08.循環結構

for of

const  fruits=["apple","babana",'orange','mongo'];
fruits.desc="my favorite fruits";//非數字索引
for (let i=0;i<fruits.length;i++){
    console.log(fruits[i]);
}

fruits.forEach(fruit=>{
    console.log(fruit)
    if(fruit == 'babana'){   //沒法終止跳出

    }
})
//非數字索引也會被遍歷出來，原型裏的也會被遍歷出來
for(let index in fruits){
    console.log(fruits[index])
}

for(let fruit of fruits){
    console.log(fruit)
}

數組迭代器

const  fruits=["apple","babana",'orange','mongo'];

for(let fruit of fruits.entries()){
    console.log(fruit); //數組 
}
for(let [index,fruit] of fruits.entries()){
    console.log(index,fruit)
}

for of暫不支持對象,nodelist(document.querySelectorAll())也可使用

打印字符串

let lan='javascript'
for (let c of lan){
    console.log(c)
}