JavaScript ES6 Useful Examples

In the examples below we show useful javascript ES6 examples which are very valuable Including:

• Array Loop and Slice
• Regular expression, replaces all blanks & special characters
• Object Keys & Values
• Object Map
• Math Sign
• Palindrom example
• Every & Some
• Array map elements
• Array Foreach loop
• map, filter, find
• reverse String
• balanceParser example

//////Loop and Slice
    var array=[1,2,3];
    for (let element of array) {
        console.log(element);
    }
    console.log(array.slice(0,2)); //0,1
//////regular expression, replaces all blanks & special characters.
let word = "hi there!!!!";
console.log(word.replace(/[^\w]/g,""));
//////Object Keys & Values
const obj = {"a": 1, "b" : "ff", c:55};
console.log(Object.keys(obj));
console.log(Object.values(obj));
//////Math Sign
console.log(Math.sign(4000));
console.log(Math.sign(-4000));
///////
function reverseInt(n) {
    return Math.sign(n) * parseInt(n.toString().split('').reverse().join(''));
}
console.log(reverseInt(-123456));
///////Object Map
const str = "aba";
const charsMap = {};
for (let char of str) {
    charsMap[char] = charsMap[char] + 1 || 1;
}
for (let item in charsMap) {
    console.log(item + ": " + charsMap[item]);
}
////////////palindrom
function palindrom(str) {
    return str === str.split('').reverse().join('');
}
console.log("palindrom aba is: " + palindrom('aba'));
/////////////Every & Some

var arr=[1,2,3];
console.log("every [1,2,3] > 2 is: " + arr.every((val)=> val>2));
console.log("some [1,2,3] > 2 is: " + arr.some((val)=> val>2));
/////////////Array map elements
var arr=[1,2,3];
arr = arr.map((item)=> {
    return item*2;
});
console.log(arr);
/////////////Array Foreach loop
var arr=[2,4,6];
var sum = 0;
arr.forEach((item)=> {
    sum += item;
});
console.log(sum);
/////////////map, filter, find
var cars = [{m: 'c', p:10}, {m: 'k', p:20}];
var prices = cars.map((car) => {
    return car.p;
})
console.log(prices);
var f = cars.filter((car) => {
    return car.p < 11; }) console.log(f); var f = cars.find((car) => {
    return car.p == 10;
})
console.log(f);
/////////reverse String
function reverseStr(str) {
    return str.split('').reduce((previousValue, currentValue)=> {
        return currentValue + previousValue;
    }, '');
}
console.log(reverseStr("testword"));
////
function balanceParser(str) {
    return !str.split('').reduce((previousValue, currentValue)=> {
        if (previousValue < 0) { return previousValue; }
        if (currentValue === '(') { return ++previousValue; };
        if (currentValue === ')') { return --previousValue; };
        return currentValue + previousValue;
    }, 0);
}
console.log(balanceParser("(())"));