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Javascript, what's wrong with this for loop syntax?

Can anyone help me?

I am currently learning Javascript and I do not understand what happened to the following piece of code:

var names = ["vasco", "joão", "francisco", "rita", "manuel"];
for (var i = 0; i < 4; i++); {
  console.log("I know someone called " + names[i] + ".");
}
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5 answers


because you end the for loop with a semicolon (;), so the for loop is separated by its block.

then

Ques1. What happens next when the code runs?

Ans. when execution is done for a loop, the loop executes until i reaches 4 . then the next block statement is executed.



Ques2. Why is "manuel" printed in o / p?

Answer

Ans. simple because the loop closes when the value i go to 4 , so

console.log("I know someone called " + names[i] + ".");         //it prints the arr[4]
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You have; at the end of yours, just remove it



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JavaScript arrays are zero-indexed. This means that the element at the very first position is in the index 0

. To target this item, you can link to it as names[0]

. In your loop, you are iterating i < 4

, meaning that once i

becomes 4, the loop stops and does not continue. This way you console.log

only call 4 times. A common practice when iterating through an array is to say i < names.length

. There are also a couple of syntax errors as others have pointed out. Below is a working version.

for (var i=0; i < names.length; i++) {
    console.log ("I know someone called"+" "+names[i]+"."); 
}
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Please remove the semicolon after:

var names=["vasco","joão","francisco","rita","manuel"];

for ( var i=0; i <5 ; i ++) {
    console.log ("I know someone called"+" "+names[i]+"."); 
}

also the condition i <4 is the stop of the last case

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there are two questions with the code you wrote,

1- you have a semicolon after the condition for(condition);

 causing the loop to do nothing

2- you are off by one, the last element of the array has a 4

 condition index must be (i <= 4)

or(i < array.length) 

var names = ["vasco", "joão", "francisco", "rita", "manuel"];
for (var i = 0; i < names.length; i++){
  console.log("I know someone called " + names[i] + ".");
}
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