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Start your free trialMarquis Briggs
8,967 PointsUsing reduce, return the total phone numbers with a 503 area code. Store the total in the variable numberOf503.
Not sure what the problem is
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 = phoneNumbersreduce(count, phoneNumber) =>
(phoneNumber.includes('(503)')){
count +=1;
}
return count;
},0);
1 Answer
Juan Luna Ramirez
9,038 Pointsconst phoneNumbers = ["(503) 123-4567", "(646) 123-4567", "(503) 987-6543", "(503) 234-5678", "(212) 123-4567", "(416) 123-4567"];
let numberOf503;
// 1. forgot the period between phoneNumbers and reduce
// 2. take care when passing in a function to another function.
// You are missing a parentheses for the arguments. Also the
// curly braces for the body of the reducer function.
numberof503 = phoneNumbers.reduce((count, phoneNumber) => {
// 4. use if statement
if (phoneNumber.includes('(503)')){
count +=1;
}
return count;
} ,0);
I often mess up the syntax for the reducer function so usually I will do this:
-
setup an empty reducer function as the first argument and the initial value as the second argument of
reduce
numberOf503 = phoneNumbers.reduce(() => {}, 0)
-
add the accumulator and item parameters to the reducer function
numberOf503 = phoneNumbers.reduce((count, phoneNumber) => {}, 0)
-
break up at the body and begin writing the body of the reducer function
numberOf503 = phoneNumbers.reduce((count, phoneNumber) => { // reducer function logic here }, 0)