循環僅在5個項目列於陣列本10個元素的

Question

我有一個數組內的10個對象如下：

let arr = [{"id":1, "name": "abc"},{"id":2, "name": "fsd"},{"id":3, "name": "fasd"},{"id":4, "name": "fsdfas"},{"id":5, "name": "fad"},{"id":6, "name": "fasdf"},{"id":7, "name": "fasd"},{"id":8, "name": "fasdf"},{"id":9, "name": "fasdfs"},{"id":10, "name": "abc"}] 

我的查詢：我想在陣列內遍歷僅第一5個目的和打破循環。 任何幫助將不勝感激。

Answer 1

老同學：

let arr = [{"id":1, "name": "abc"},{"id":2, "name": "fsd"},{"id":3, "name": "fasd"},{"id":4, "name": "fsdfas"},{"id":5, "name": "fad"},{"id":6, "name": "fasdf"},{"id":7, "name": "fasd"},{"id":8, "name": "fasdf"},{"id":9, "name": "fasdfs"},{"id":10, "name": "abc"}] 
 

 
// Math.min (just in case arr.length < 5) 
 
for (let i = 0; i < Math.min(5, arr.length); i++) { 
 
    console.log(arr[i]); 
 
}

Answer 2

let arr = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']; 
 
for (let i = 0; i < 5; i++) { 
 
    console.log(arr[i]); 
 
}

看起來你正在使用ES2015 +，所以要注意let i在for循環的限制。這可以避免i變量泄漏到外部範圍中的值。

Answer 3

你可以試試這個。

let arr = [{"id":1, "name": "abc"},{"id":2, "name": "fsd"},{"id":3, "name": "fasd"},{"id":4, "name": "fsdfas"},{"id":5, "name": "fad"},{"id":6, "name": "fasdf"},{"id":7, "name": "fasd"},{"id":8, "name": "fasdf"},{"id":9, "name": "fasdfs"},{"id":10, "name": "abc"}] 
 

 
arr.slice(0, 5).forEach(item => console.log(item));