Advanced Array Methods(some & every)

some

: Iterates through an array

  Runs a callback on each value in the array

  If the callback returns true for at least one single value, return true

  Otherwise, return false

The result of the callback will ALWAYS be a boolean

function some(array, callback){

for (var i = 0; i <array.length; i++){

if(callback(array[i], i , array)){

return true;

}

}

return false;

}

every

: Iterates through an array

  Runs a callback on each value in the array

  If the callback returns false for any single value, return false

  Otherwise, return true

The result of the callback will ALWAYS be a boolean

function every(array, callback){

for(var i =0; i < array.length; i++){

if(callback(array[i], i, array) === false) {

return false;

}

}

return true;

}

/*

Write a function called hasOddNumber which accepts an array and returns true if the array contains at least one odd number, otherwise it returns false.

Examples:

    hasOddNumber([1,2,2,2,2,2,4]) // true

    hasOddNumber([2,2,2,2,2,4]) // false

*/

function hasOddNumber(arr){

   return arr.some(function(val){

        return val % 2 !== 0 ;

    });

}

/*

Write a function called hasAZero which accepts a number and returns true if that number contains at least one zero. Otherwise, the function should return false

Examples:

    hasAZero(3332123213101232321) // true

    hasAZero(1212121) // false

*/

function hasAZero(num){

    arr.some(function(val){             >return num.toString().split('').some(function(val){           

        return val[key] === 0;        > return val === "0";

    });

}

/*

Write a function called hasOnlyOddNumbers which accepts an array and returns true if every single number in the array is odd. If any of the values in the array are not odd, the function should return false. 

Examples:

    hasOnlyOddNumbers([1,3,5,7]) // true

    hasOnlyOddNumbers([1,2,3,5,7]) // false

*/

function hasOnlyOddNumbers(arr){

   return arr.every(function(val){

        return val % 2 !==0;

    });

}

/*

Write a function called hasNoDuplicates which accepts an array and returns true if there are no duplicate values (more than one element in the array that has the same value as another). If there are any duplicates, the function should return false.

Examples:

    hasNoDuplicates([1,2,3,1]) // false

    hasNoDuplicates([1,2,3]) // true

*/

function hasNoDuplicates(arr){

    return arr.every(function(val){

        return val === val[i];        >    return arr.indexOf(val) === arr.lastIndexOf(val);

    });

}

/*

Write a function called hasCertainKey which accepts an array of objects and a key, and returns true if every single object in the array contains that key. Otherwise it should return false.

Examples:

    var arr = [

        {title: "Instructor", first: 'Elie', last:"Schoppik"}, 

        {title: "Instructor", first: 'Tim', last:"Garcia", isCatOwner: true}, 

        {title: "Instructor", first: 'Matt', last:"Lane"}, 

        {title: "Instructor", first: 'Colt', last:"Steele", isCatOwner: true}

    ]

    

    hasCertainKey(arr,'first') // true

    hasCertainKey(arr,'isCatOwner') // false

*/

function hasCertainKey(arr, key){

    return arr.every(function(val, key){        >        return arr.every(function(val){        

        return val;        >        return key in val;

    })

}

/*

Write a function called hasCertainValue which accepts an array of objects and a key, and a value, and returns true if every single object in the array contains that value for the specific key. Otherwise it should return false.

Examples:

    var arr = [

        {title: "Instructor", first: 'Elie', last:"Schoppik"}, 

        {title: "Instructor", first: 'Tim', last:"Garcia", isCatOwner: true}, 

        {title: "Instructor", first: 'Matt', last:"Lane"}, 

        {title: "Instructor", first: 'Colt', last:"Steele", isCatOwner: true}

    ]

   

    hasCertainValue(arr,'title','Instructor') // true

    hasCertainValue(arr,'first','Elie') // false

    

*/

function hasCertainValue(arr, key, searchValue){

    return arr.every(function(val){

return val[key] === searchValue;

}