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Iterate (loop) over the properties of an object
The for...in statements combo iterates (loops) over the properties of an object.
The code block inside the loop is executed once for each property.
Do not use for...in to iterate an array if the index order is important. Use a for loop instead.
| Parameter | Description |
| x | Required. A variable to iterate over the properties. |
| object | Required. The object to be iterated |
| Statement | Description | |
| break | Breaks out of a loop | |
| continue | Skips a value in a loop | |
| while | Loops a code block while a condition is true | |
| do...while | Loops a code block once, and then while a condition is true | |
| for | Loops a code block while a condition is true | |
| for...of | Loops the values of any iterable | |
| for...in | Loops the properties of an object |
Iterate over the properties of window.location:
let text = "";
for (let x in location) {
text += x + "
";
}
document.getElementById("demo").innerHTML = text;
for...in is an ECMAScript1 (ES1) feature.
ES1 (JavaScript 1997) is fully supported in all browsers:
| Chrome | IE | Edge | Firefox | Safari | Opera |
| Yes | Yes | Yes | Yes | Yes | Yes |