获取数组中的第一项和最后一项-JS [英] Get the first and last item in an Array - JS
本文介绍了获取数组中的第一项和最后一项-JS的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我试图获取数组中的第一个和最后一个项目并将它们显示在一个对象中。
我所做的是我使用了第一个和最后一个函数,然后将第一项分配为键,最后一项分配为值。
var myArray = ['Rodel','Mike ','Ronnie','Betus'];
函数firstAndLast(array){
var firstItem = myArray.first;
var lastItem = myArray.last;
var objOutput = {
firstItem:lastItem
};
}
var display = transformFirstAndLast(myArray);
console.log(display);
无论如何这都会给我带来麻烦。它说未定义。知道为什么吗?
解决方案
我修改了您的代码:
< pre class = snippet-code-js lang-js prettyprint-override>
var myArray = ['Rodel','Mike','Ronnie','Betus'];函数firstAndLast(array){ var firstItem = myArray [0]; var lastItem = myArray [myArray.length-1]; var objOutput = {first:firstItem,last:lastItem};返回objOutput;} var display = firstAndLast(myArray); console.log(display);
更新:新修改
var myArray = ['Rodel','Mike','Ronnie','Betus'];函数firstAndLast(array){var firstItem = myArray [0]; var lastItem = myArray [myArray.length-1]; var objOutput = {}; objOutput [firstItem] = lastItemreturn objOutput;} var display = firstAndLast(myArray); console.log(display);
I am trying to get the first and last item in array and display them in an object.
What i did is that I use the first and last function and then assign the first item as the key and the last item as the value.
var myArray = ['Rodel', 'Mike', 'Ronnie', 'Betus'];
function firstAndLast(array) {
var firstItem = myArray.first;
var lastItem = myArray.last;
var objOutput = {
firstItem : lastItem
};
}
var display = transformFirstAndLast(myArray);
console.log(display);
however this one gets me into trouble. It says undefined. Any idea why is that?
解决方案
I've modified your code :
var myArray = ['Rodel', 'Mike', 'Ronnie', 'Betus'];
function firstAndLast(array) {
var firstItem = myArray[0];
var lastItem = myArray[myArray.length-1];
var objOutput = {
first : firstItem,
last : lastItem
};
return objOutput;
}
var display = firstAndLast(myArray);
console.log(display);
UPDATE: New Modification
var myArray = ['Rodel', 'Mike', 'Ronnie', 'Betus'];
function firstAndLast(array) {
var firstItem = myArray[0];
var lastItem = myArray[myArray.length-1];
var objOutput = {};
objOutput[firstItem]=lastItem
return objOutput;
}
var display = firstAndLast(myArray);
console.log(display);
这篇关于获取数组中的第一项和最后一项-JS的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文