Example 1: javascript loop through object example
var person={
first_name:"johnny",
last_name: "johnson",
phone:"703-3424-1111"
};
for (var property in person) {
console.log(property,":",person[property]);
}
Example 2: javascript loop through array of objects
let arr = [object0, object1, object2];
for (let elm of arr) {
console.log(elm);
}
Example 3: js loop over array of objects extract value
var myArr = [{name: 'rich', secondName: 'james'}, {name: 'brian', secondName: 'chris'}];
var mySecondArr = myArr.map(x => x.name);
console.log(mySecondArr);
Example 4: js loop array of objects
const p = [{
"p1": "value1",
"p2": "value2",
"p3": "value3"
},
{
"p4": "value4",
"p5": "value5",
"p6": "value6"
}];
for (let obj of p) {
for(let key in obj) {
console.log(key);
}
}
Example 5: loop array of objects
const myArray = [{x:100}, {x:200}, {x:300}];
const newArray= myArray.map(element => {
return {
...element,
x: element.x * 2
};
});
console.log(myArray);
console.log(newArray);
Example 6: iterate over array of objects javascript
const people = [
{name: 'John', group: 'A'},
{name: 'Andrew', group: 'C'},
{name: 'Peter', group: 'A'},
{name: 'James', group: 'B'},
{name: 'Hanna', group: 'A'},
{name: 'Adam', group: 'B'}];
const groupInfo = people.reduce((groups, person) => {
const {A = 0, B = 0, C = 0} = groups;
if (person.group === 'A') {
return {...groups, A: A + 1};
} else if (person.group === 'B') {
return {...groups, B: B + 1};
} else {
return {...groups, C: C + 1};
}
}, {});
console.log(groupInfo);