I have an array and simply want to get the element at index 1.
var myValues = new Array();
var valueAtIndex1 = myValues.getValue(1); // (something like this)
How can I get the value at the 1st index of my array in JavaScript?
只需使用indexer
var valueAtIndex1 = myValues[1];
Array indexes in JavaScript start at zero for the first item, so try this:
var firstArrayItem = myValues[0]
Of course, if you actually want the second item in the array at index 1, then it's myValues[1]
.
See Accessing array elements for more info.
你可以只使用[]
:
var valueAtIndex1 = myValues[1];
indexer ( array[index]
) is the most frequent use. An alternative is at
array method:
const cart = ['apple', 'banana', 'pear'];
cart.at(0) // 'apple'
cart.at(2) // 'pear'
If you come from another programming language, maybe it looks more familiar.
您可以使用[];
var indexValue = Index[1];
shift
can be used in places where you want to get the first element ( index=0
) of an array and chain with other array methods.
example:
const comps = [{}, {}, {}]
const specComp = comps
.map(fn1)
.filter(fn2)
.shift()
Remember shift
mutates the array, which is very different from accessing via an indexer.
With ES2022 you can use Array.prototype.at()
:
const myValues = [1, 2, 3]
myValues.at(1) // 2
at()
also supports negative index, which returns an element from the end of the array:
const myValues = [1, 2, 3]
myValues.at(-1) // 3
myValues.at(-2) // 2
Read more: MDN , JavascriptTutorial , Specifications
As you specifically want to get the element at index 1. You can also achieve this by using Array destructuring from ES6.
const arr = [1, 2, 3, 4];
const [zeroIndex, firstIndex, ...remaining] = arr;
console.log(firstIndex); // 2
Or, As per ES2022. You can also use Array.at()
const arr = [1, 2, 3, 4];
console.log(arr.at(1)); // 2
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