Mastering in Javascript | Conditionals

This will is a common condition to check the object array contains the same value for value or not for a key, so lets take an example as follows:

const jar = [
    { name: 'orange', color: 'orange' },
    { name: 'apple', color: 'red' },
    { name: 'guava', color: 'green' }
  ];

function check() {
  let isAllRed = true;

  // condition: all fruits must be red
  for (let f of jar) {
    if (!isAllRed) break;
    isAllRed = (f.color == 'red');
  }

  console.log(isAllRed); // false
}

check();

If you see the code we have to check whether each array element color is red or not.

So we did the loop on each element and added the flag to check whether its true or not, but the code is so long, we can reduce it using Array.every() function.

Much easier and cleaner right? 

Using Array.some for conditioning object array elements:

Now, let’s take above example, you have to check whether jar contains red color or not so you can easily write that condition with the following code.

function check() {

  const isAllRed = jar.some(fruit => fruit.color == 'red');

  console.log(isAllRed); // true
}

check();

Much easy right?

if you want to check multiple conditions like if the fruit is apple or banana etc then we use the following statements to check.

if you see the code you are checking with apple and banana only what if you have to add more fruits to check then again you have to add more || operator right?

So let’s use Array.includes to handle this condition.

function test(fruit) {
  // extract conditions to array
  const redFruits = ['apple', 'strawberry', 'cherry', 'cranberries'];

  if (redFruits.includes(fruit)) {
    console.log('red');
  }
}

isn’t it easy and maintainable? We can extract the element from an array.

That’s it for this post.

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Thanks and comment if you want to some clarifications. 

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