I have this object. I want to iterate this object in JavaScript. How is this possible?
var dictionary = {
"data": [
{"id":"0","name":"ABC"},
{"id":"1","name":"DEF"}
],
"images": [
{"id":"0","name":"PQR"},
{"id":"1","name":"xyz"}
]
};
You can do it with the below code. You first get the data array using dictionary.data and assign it to the data variable. After that you can iterate it using a normal for loop. Each row will be a row object in the array.
var data = dictionary.data;
for (var i in data)
{
var id = data[i].id;
var name = data[i].name;
}
You can follow similar approach to iterate the image array.
dictionary.data and just iterate over dictionary
for...in is for iterating over object properties. For arrays, use for...of instead.There's this way too (new to EcmaScript5):
dictionary.data.forEach(function(item){
console.log(item.name + ' ' + item.id);
});
Same approach for images
Something like that:
var dictionary = {"data":[{"id":"0","name":"ABC"},{"id":"1", "name":"DEF"}], "images": [{"id":"0","name":"PQR"},{"id":"1","name":"xyz"}]};
for (item in dictionary) {
for (subItem in dictionary[item]) {
console.log(dictionary[item][subItem].id);
console.log(dictionary[item][subItem].name);
}
}
Use dot notation and/or bracket notation to access object properties and for loops to iterate arrays:
var d, i;
for (i = 0; i < dictionary.data.length; i++) {
d = dictionary.data[i];
alert(d.id + ' ' + d.name);
}
You can also iterate arrays using for..in loops; however, properties added to Array.prototype may show through, and you may not necessarily get array elements in their correct order, or even in any consistent order.
Using a generator function you could iterate over deep key-values.
function * deepEntries(obj) {
for(let [key, value] of Object.entries(obj)) {
if (typeof value !== 'object')
yield [key, value]
else
for(let entries of deepEntries(value))
yield [key, ...entries]
}
}
const dictionary = {
"data": [
{"id":"0","name":"ABC"},
{"id":"1","name":"DEF"}
],
"images": [
{"id":"0","name":"PQR"},
{"id":"1","name":"xyz"}
]
}
for(let entries of deepEntries(dictionary)) {
const key = entries.slice(0, -1).join('.')
const value = entries[entries.length-1]
console.log(key, value)
}
for(index in dictionary) {
for(var index in dictionary[]){
// do something
}
}
Using for and foreach loop
var dictionary = {
data: [{ id: "0", name: "ABC" }, { id: "1", name: "DEF" }],
images: [{ id: "0", name: "PQR" }, { id: "1", name: "xyz" }]
};
dictionary.data.forEach(item => {
console.log(item.id + " " + item.name);
});
for (var i = 0; i < dictionary.data.length; i++) {
console.log(dictionary.data[i].id + " " + dictionary.data[i].name);
}
var dictionary = {
"data":[{"id":"0","name":"ABC"}, {"id":"1","name":"DEF"}],
"images": [ {"id":"0","name":"PQR"},"id":"1","name":"xyz"}]
};
for (var key in dictionary) {
var getKey = dictionary[key];
getKey.forEach(function(item) {
console.log(item.name + ' ' + item.id);
});
}
Here's all the options you have:
for...of (ES2015)var dictionary = {
"data": [
{"id":"0","name":"ABC"},
{"id":"1","name":"DEF"}
],
"images": [
{"id":"0","name":"PQR"},
{"id":"1","name":"xyz"}
]
};
for (const entry of dictionary.data) {
console.log(JSON.stringify(entry))
}Array.prototype.forEach (ES5)var dictionary = {
"data": [
{"id":"0","name":"ABC"},
{"id":"1","name":"DEF"}
],
"images": [
{"id":"0","name":"PQR"},
{"id":"1","name":"xyz"}
]
};
dictionary.data.forEach(function(entry) {
console.log(JSON.stringify(entry))
})for() (ES1)var dictionary = {
"data": [
{"id":"0","name":"ABC"},
{"id":"1","name":"DEF"}
],
"images": [
{"id":"0","name":"PQR"},
{"id":"1","name":"xyz"}
]
};
for (let i = 0; i < dictionary.data.length; i++) {
console.log(JSON.stringify(dictionary.data[i]))
}