php loop: repeat just once

How can I get a php loop to print out:

1 1 2 2 3 3 all the way to 250 250. So basically count from 1 - 开发者_如何学Go250 but print out each number twice?

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for ($i = 1; $i <= 250; $i++){
   echo "$i ";
   echo "$i ";
}

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for($i = 1; $i <= 250; $i++)
{
    echo $i, ' ', $i, ($i != 250 ? ' ' : NULL);
}

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implode(' ', array_map('floor', range(1, 250.5, 0.5)));

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for ($i = 1; $i <= 250; $i++) {
    echo $i; // print the first time
    echo $i; // print the second time
}

You can obviously print duplicated value with one echo statement and make the code one line shorter.

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The approach to solve this is loop. You can use loops of 4 types in PHP while, for, do...while, foreach. Except for...each you can do it in other three ways. For each is used for arrays. I am writing all three loops.

while loop

$i = 1; // initialize a variable which can be used else where in the program
while($i<=250)
{
    echo $i."  ".$i;
 $i++;
}  

for loop

for($i = 1; $i <=250; $i++)
{
echo $i." ".$i;
}

the variable initialized in the braces of for loop can just be used with in the loop. do while loop

$i = 1;
do{
   echo $i." ".$i;
 }while($i<=250);