Javascript: Filter elements parts in Array

Question

I am trying to select all the elements in an Array that contain the word "Orange", independently of the number before.

I tried with this code, but it is only working when I write the exact element name like "02orange".

var DWArray = ["apple", "apple", "02orange", "03orange", "04orange", "potato"];

function checkOrange(orange) {
    return orange == "02orange";
}
var OrangeArray = DWArray.filter(checkOrange);
return OrangeArray.join(", ");

My desired result is:

["02orange", "03orange", "04orange"];

I suggest that you google "javascript string". The first hit is the MDN documentation which has a list of available methods. Look through this list and find one that does what you need. — Code-Apprentice, Feb 19 '19 at 21:06

Nina Scholz · Accepted Answer · 2019-02-19T21:19:10.940

2

You could return the result of the check with String#includes.

function checkOrange(orange) {
    return orange.includes("orange");
}

var DWArray = ["apple", "apple", "02orange", "03orange", "04orange", "potato"],
    OrangeArray = DWArray.filter(checkOrange);

console.log(OrangeArray.join(", "));

For older Browser, you might use String#indexOf.

function checkOrange(orange) {
    return orange.indexOf("orange") !== -1;
}

var DWArray = ["apple", "apple", "02orange", "03orange", "04orange", "potato"],
    OrangeArray = DWArray.filter(checkOrange);

console.log(OrangeArray.join(", "));

edited Feb 19 '19 at 21:19

answered Feb 19 '19 at 21:02

Nina Scholz

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I tried Includes but I have this error all the time "orange.includes is not a function in ", that is why I used filter instead – Kayra Feb 19 '19 at 21:14
do you use an older browser? – Nina Scholz Feb 19 '19 at 21:18

guest271314 · Answer 2 · 2019-02-19T21:23:09.037

2

One option would be to use RegExp constructor and RegExp.prototype.test() with string "orange" passed as first parameter and i (ignore case; if u flag is also enabled, use Unicode case folding) and g flags (global match; find all matches rather than stopping after the first match) passed as second parameter

var DWArray = ["apple", "apple", "02orange", "03orange", "04orange", "potato"];

function checkOrange(orange) {
  return new RegExp("orange", "ig").test(orange)
}

var OrangeArray = DWArray.filter(checkOrange);

console.log(OrangeArray, OrangeArray.join(", "));

edited Feb 19 '19 at 21:23

answered Feb 19 '19 at 21:03

guest271314

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Using RegExp I get this error: "cannot supply flags when constructing one regexp from another". Do you know why? Thank you – Kayra Feb 19 '19 at 21:21
@Kayra See updated post. Should be a string passed as first parameter to `RegExp` constructor – guest271314 Feb 19 '19 at 21:23
Is the `g` flag really useful since the OP only needs to know if the word contains `orange` ? +1 for the `i` flag though – jo_va Feb 19 '19 at 21:32

ellipsis · Answer 3 · 2019-02-19T21:05:30.907

0

Use .includes to check if the string includes orange in it, with filter. Refer

var DWArray = ["apple", "apple", "02orange", "03orange", "04orange", "potato"];
console.log(DWArray.filter(e=>e.includes('orange')))

edited Feb 19 '19 at 21:05

answered Feb 19 '19 at 21:01

ellipsis

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when I use "Includes" I get this error "orange.includes is not a function in ", that is why I used filter instead. Do you know why? Thank you – Kayra Feb 19 '19 at 21:22
You might find the answer to that here. https://stackoverflow.com/questions/41820770/using-includes-method-in-a-function – ellipsis Feb 19 '19 at 21:27

jo_va · Answer 4 · 2019-02-19T21:34:52.640

0

You can do it with a regex and RegExp.test() in one line:

const DWArray = ["apple", "apple", "02orange", "03orange", "04orange", "potato"];
const OrangeArray = DWArray.filter(s => /orange/i.test(s)).join(', ');

console.log(OrangeArray);

edited Feb 19 '19 at 21:34

answered Feb 19 '19 at 21:29

jo_va

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Javascript: Filter elements parts in Array

4 Answers4