checking if values in an array are next to each other js code example

Example 1: check if array has same values javascript

const allEqual = arr => arr.every(v => v === arr[0]);
allEqual([1,1,1,1]);  // true

Example 2: javascript every

const age= [2,7,12,17,21];
age.every(function(person){
return person>18;
});  //false

//es6
const age= [2,7,12,17,21];
age.every((person)=> person>18);  //false

Example 3: javascript every method

// array.every(function(elemnt)) method takes in a function 
// which evaulates each elment 
// The every method is designed to check if all the elements
// in an array meet a specific condition 
// This condition is defined within your function

let numbers = [1, 2, 3, 42, 3, 2, 4, -1];

let allPassed = numbers.every(function(element){
	return element > 0;
});

// This method returns a Boolean value
// allPassed is set to false because not all elements were greater than 0

Example 4: check if all elements in array match a condition javascript

const isBelowThreshold = (currentValue) => currentValue < 40;

const array1 = [1, 30, 39, 29, 10, 13];

console.log(array1.every(isBelowThreshold));
// expected output: true