array of objects foreach javascript code example

Example 1: javascript foreach object

const list = {
  key: "value",
  name: "lauren",
  email: "[email protected]",
  age: 30
};

// Object.keys returns an array of the keys
// for the object passed in as an argument.

Object.keys(list).forEach(val => {
  let key = val;
  let value = list[val];
  console.log(`${key} : ${value}`);
});

// Returns:
// "key : value"
// "name : lauren";
// "email : [email protected]"
// "age : 30"

Example 2: For-each over an array in JavaScript

/** 1. Use forEach and related */
var a = ["a", "b", "c"];
a.forEach(function(entry) {
    console.log(entry);
});

/** 2. Use a simple for loop */
var index;
var a = ["a", "b", "c"];
for (index = 0; index < a.length; ++index) {
    console.log(a[index]);
}

/**3. Use for-in correctly*/
// `a` is a sparse array
var key;
var a = [];
a[0] = "a";
a[10] = "b";
a[10000] = "c";
for (key in a) {
    if (a.hasOwnProperty(key)  &&        // These checks are
        /^0$|^[1-9]\d*$/.test(key) &&    // explained
        key <= 4294967294                // below
        ) {
        console.log(a[key]);
    }
}

/** 4. Use for-of (use an iterator implicitly) (ES2015+) */
const a = ["a", "b", "c"];
for (const val of a) {
    console.log(val);
}

/** 5. Use an iterator explicitly (ES2015+) */
const a = ["a", "b", "c"];
const it = a.values();
let entry;
while (!(entry = it.next()).done) {
    console.log(entry.value);
}

Example 3: foreach javascript

let words = ['one', 'two', 'three', 'four'];
words.forEach((word) => {
  console.log(word);
});
// one
// two
// three
// four

Example 4: js for each item do

let array = ['Item 1', 'Item 2', 'Item 3'];

array.forEach(item => {
	console.log(item); // Logs each 'Item #'
});

Example 5: javascript foreach object

function logArrayElements(element, index, array) {
  console.log('a[' + index + '] = ' + element)
}

// Notice that index 2 is skipped, since there is no item at
// that position in the array...
[2, 5, , 9].forEach(logArrayElements)
// logs:
// a[0] = 2
// a[1] = 5
// a[3] = 9

Example 6: foreach javascript

Used to execute the same code on every element in an array
Does not change the array
Returns undefined

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