我想知道是否有一种方法可以在JavaScript中做一些类似PHP foreach循环的事情。我正在寻找的功能是类似这样的PHP代码片段:
foreach($data as $key => $value) { }
我在看JS for. in循环,但似乎没有办法指定as。如果我用一个'normal' for循环(for(var I = 0;I < data.length;i++),有办法抓取键=>值对吗?
我想知道是否有一种方法可以在JavaScript中做一些类似PHP foreach循环的事情。我正在寻找的功能是类似这样的PHP代码片段:
foreach($data as $key => $value) { }
我在看JS for. in循环,但似乎没有办法指定as。如果我用一个'normal' for循环(for(var I = 0;I < data.length;i++),有办法抓取键=>值对吗?
当前回答
let test = {a: 1, b: 2, c: 3};
Object.entries(test).forEach(([key, value]) => console.log(key, value))
// a 1
// b 2
// c 3
其他回答
下面是一个非常接近的例子。
for(var key in data){
var value = data[key];
//your processing here
}
如果你正在使用jQuery,请访问:http://api.jquery.com/jQuery.each/
是的,在javascript中你也可以有关联数组:
var obj =
{
name:'some name',
otherProperty:'prop value',
date: new Date()
};
for(i in obj)
{
var propVal = obj[i]; // i is the key, and obj[i] is the value ...
}
你可以使用'for in'循环来实现:
for (var key in bar) {
var value = bar[key];
}
没有人提到Object。钥匙,所以我会提到它。
Object.keys(obj).forEach(function (key) {
// do something with obj[key]
});
var global = (function() {
return this;
})();
// Pair object, similar to Python
function Pair(key, value) {
this.key = key;
this.value = value;
this.toString = function() {
return "(" + key + ", " + value + ")";
};
}
/**
* as function
* @param {String} dataName A String holding the name of your pairs list.
* @return {Array:Pair} The data list filled
* with all pair objects.
*/
Object.prototype.as = function(dataName) {
var value, key, data;
global[dataName] = data = [];
for (key in this) {
if (this.hasOwnProperty(key)) {
value = this[key];
(function() {
var k = key,
v = value;
data.push(new Pair(k, v));
})();
}
}
return data;
};
var d = {
'one': 1,
'two': 2
};
// Loop on your (key, list) pairs in this way
for (var i = 0, max = d.as("data").length; i < max; i += 1) {
key = data[i].key;
value = data[i].value;
console.log("key: " + key + ", value: " + value);
}
// delete data when u've finished with it.
delete data;