CODEWITHSUNDEEP
javascriptarrays
UndefinedUsername
UndefinedUsername

Reputation: 157

Find information from an array using another array

I currently have this problem where I cannot seem to find an answer specific to my problem.

Array1 = ["item1", "item2", "item3", "item4", "item5"]
Array2 = ["item2", "item5"]

I am looking to use the information from array2 to find within array1.

An example for this to output

Array1 has item2 and is at Array1[1]

If anyone can help me, thank you.

Upvotes: 0

Views: 62

Answers (4)

Marcus Vinícius Monteiro
Marcus Vinícius Monteiro

Reputation: 8069

Array2.forEach((e) => {
    const indexOfE = Array1.indexOf(e)
    if (indexOfE > -1) {
        console.log(`Array1 has ${e} and is at Array1[${indexOfE}]`)
    }
})

You can have a look at forEach, indexOf, and template literals to help you understand this code.

Edit

Answering the question in the comments, if you want to check the elements in Array1 that contain elements of Array2 as substrings, then you can:

Array2.forEach((e) => {
    Array1.forEach((f, i) => {
        if (f.toLowerCase().includes(e)) {
            console.log(`Array1 has ${e} and is at Array1[${i}]`)
        }
    })
})

Check String.prototype.includes and this answer for details on finding substrings in another String.

Upvotes: 2

user93
user93

Reputation: 1866

You could Ramdajs to find intersection of two arrays as follows

const Array1 = ["item1", "item2", "item3", "item4", "item5"];
const Array2 = ["item2", "item5"];

const res = R.intersection(Array1, Array2);
console.log(res);

here is the code repel

The same could be achieved using lodash 

const Array1 = ["item1", "item2", "item3", "item4", "item5"];
const Array2 = ["item2", "item5"];
const res = _.intersection(Array1, Array2)
console.log(res);

here is the jsfiddle for lodash.

or you could use the includes method of the array to do the same

const Array1 = ["item1", "item2", "item3", "item4", "item5"];
const Array2 = ["item2", "item5"];
const res = Array1.filter(curr=>Array2.includes(curr));
console.log(res);

Upvotes: 0

shangzhouwan
shangzhouwan

Reputation: 246

This is the code:

var Array1 = ["item1", "item2", "item3", "item4", "item5"];
var Array2 = ["item2", "item5"];
for (var i = 0; i <Array2.length; i++) {
 if (Array1.indexOf(Array2[i])>-1) {
 console.log("Array1 has "+Array2[i]+" and is at Array1["+Array1.indexOf(Array2[i]) +"]")  
  }
}

Upvotes: 0

Chris Cousins
Chris Cousins

Reputation: 1912

If you only want to know Array1 contains an element from Array2 then iterate over Array2 calling indexOf for each element:

Array2.map((el => {
    if (Array1.indexOf(el) !== -1) {
        console.log('Array 1 contains ' + el);
    }
}));

Upvotes: 0

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