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JavaScript JavaScript Array Iteration Methods Array Manipulation Practice reduce()

Posted by Shreemangal Sethi
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Shreemangal Sethi
Full Stack JavaScript Techdegree Student 15,552 Points

How do i check for equality?

I am not sure if i am checking the equality correctly. I have tried number.substring(0, 3) === 503, number[0] === '5' and number[0].equals('5') but nothing seems to work.

app.js 
const phoneNumbers = ["(503) 123-4567", "(646) 123-4567", "(503) 987-6543", "(503) 234-5678", "(212) 123-4567", "(416) 123-4567"];
let numberOf503;

// numberOf503 should be: 3
// Write your code below

numberOf503 = phoneNumbers.reduce((count, number) => {

  if(number[0].equals('5') ){
    return count+1
  }
  return count
},0);

1 Answer

Blake Larson
Blake Larson
13,014 Points
Blake Larson
Blake Larson
13,014 Points

Just remember that the first index of each array item is ( so you don't want to start at 0 on the phone number strings and you will want to compare it to another string.

substring return value === '503'