Javascript array: How to check if two consecutive words are the same?

Question

I want my program to check if any two consecutive words in the array are the same. I believe that my "if" statement is correct, however the console.log shows that all consecutive words match. What am I miss here?

Any help appreciated! I'm new to this stuff :)

var wordArray = ["blue", "green", "yellow", "red", "red", "blue", "blue", "yellow"]

for (i=0; i<wordArray.length - 1; i++) {
    if (i === i+1); {
        console.log("We have a match!");
    } //Why is this loop saying that all items in the array are equal?
}

Nina Scholz · Accepted Answer · 2015-11-19 17:12:55Z

5

Try this. You were checking the index and not the element of the array, beside the wrong if statement.

for (i = 0; i < wordArray.length - 1; i++) {
    if (wordArray[i] === wordArray[i + 1]) {
        console.log("We have a match!");
    }
}

Just a hint for better length handling, if the array is only one element long:

for (i = 1; i < wordArray.length; i++) {
    if (wordArray[i - 1] === wordArray[i]) {
        console.log("We have a match!");
    }
}

edited Nov 19, 2015 at 17:12

answered Nov 19, 2015 at 17:03

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Azad · Accepted Answer · 2015-11-19 17:08:34Z

0

try this,

var wordArray = ["blue", "green", "yellow", "red", "red", "blue", "blue", "yellow"]

for (i=1; i<wordArray.length; i++) {
    if (wordArray[i] === wordArray[i-1]) {
        console.log("We have a match!");
    }
}

edited Nov 19, 2015 at 17:08

answered Nov 19, 2015 at 17:05

Azad

5,2725 gold badges32 silver badges59 bronze badges

4 Comments

Nina Scholz Over a year ago

watch the ; after if

Azad Over a year ago

@NinaScholz yep I missed,

Azad Over a year ago

@Halcyon I testing with previous word so, it should go until last.

Halcyon Over a year ago

@Azzi ok, that works. Why did you decide to flip it around?

devduderino · Accepted Answer · 2015-11-19 17:12:35Z

0

It looks like you are actually comparing your index var "i" to "i + 1" in your code resulting in your console saying all items in the array are equal. Since you are actually comparing the index var , your Javascript is seeing this as :

if(1 === 2) 
    console.log("We have a match");

Since you actually want to compare the contents of wordArray :

if(wordArray[i] === wordArray[i + 1])
     console.log("We have a match!");

The important thing to remember here is that when using a "for" loop , the index variable ,"i" in this case, is only going to be an integer index for accessing the contents of the array.

answered Nov 19, 2015 at 17:12

devduderino

714 bronze badges

Collectives™ on Stack Overflow

Javascript array: How to check if two consecutive words are the same?

3 Answers 3

Comments

4 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related