获取数组中每个元素的长度 - JavaScript
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Get length of every element in array - JavaScript
提问by HyperScripts
I want to get length of every element in array
我想获取数组中每个元素的长度
my code is
我的代码是
var a = "Hello world" ;
var chars = a.split(' ');
so I will have an array of
所以我会有一个数组
chars = ['Hello' , 'world'] ;
but how I can get length of each word like this ?
但是我怎么能像这样得到每个单词的长度？
Hello = 5
world = 5
采纳答案by juvian
You can use map Array function:
您可以使用 map Array 函数：
var lengths = chars.map(function(word){
return word.length
})
回答by nils
You could create a results object (so you have the key, "hello", and the length, 5):
您可以创建一个结果对象（因此您有键“hello”和长度 5）：
function getLengthOfWords(str) {
var results = {};
var chars = str.split(' ');
chars.forEach(function(item) {
results[item] = item.length;
});
return results;
}
getLengthOfWords("Hello world"); // {'hello': 5, 'world': 5}
回答by uksz
The key here is to use .length property of a string:
这里的关键是使用字符串的 .length 属性：
for (var i=0;i<chars.length;i++){
console.log(chars[i].length);
}
回答by AmmarCSE
回答by Stephen P
ES6 is now widely available (2019-10-03) so for completeness — you can use the arrow operatorwith .map()
ES6是现在广泛使用（2019年10月3日），因此设备的完整性-你可以使用箭头操作符与.map()
var words = [ "Hello", "World", "I", "am", "here" ];
words.map(w => w.length);
> Array [ 5, 5, 1, 2, 4 ]
or, very succinctly
或者，非常简洁
"Hello World I am here".split(' ').map(w => w.length)
> Array [ 5, 5, 1, 2, 4 ]
回答by Hanlet Esca?o
You can use forEach, if you want to keep the words, and the length you can do it like this:
你可以使用forEach，如果你想保留的话，你可以这样做的长度：
var a = "Hello world" ;
var chars = a.split(' ');
var words = [];
chars.forEach(function(str) {
words.push([str, str.length]);
});
You can then access both the size and the word in the array.
然后您可以访问数组中的大小和单词。
Optionally you could have a little POJO object, for easier access:
或者，您可以有一个小的 POJO 对象，以便于访问：
var a = "Hello world" ;
var chars = a.split(' ');
var words = [];
chars.forEach(function(str) {
words.push({word: str, length: str.length});
});
Then you can access them like:
然后你可以像这样访问它们：
console.log(words[0].length); //5
console.log(words[0].word); //"Hello"
Or using mapto get the same POJO:
或者使用map来获取相同的 POJO：
var words = chars.map(function(str) {
return {word: str, length: str.length};
});
