如何确定整数是否在范围内并存储到两个数组中？

Question

I have an array called $grades which contains grades ranging from negative numbers to numbers over 100.

I need to put the negative grades and the grades over 100 into their own array and all the other numbers into their own array.

for($i = 0; $i < count($grades); $i++) {
    if ($grades[$i] < 0 || $grades[$i] > 100) {
        $invalidGrades[] = $i;
    } else if ($grades[$i] >= 0 && $grades[$i] <= 100) {
        $validGrades[] = $i;
    }
}

This is the code I have so far. It appears to only be returning the numbers in the count instead of the values.

Answer 1

could be you want assign the grades using same index you can try this way

for($i = 0; $i < count($grades); $i++) {

      if ($grades[$i] < 0 || $grades[$i] > 100) {
          $invalidGrades[$i] =  $grades[$i];
      } else if ($grades[$i] >= 0 && $grades[$i] <= 100) {
          $validGrades[$i] = $grades[$i];
      }
}

or if you want push the value

for($i = 0; $i < count($grades); $i++) {

      if ($grades[$i] < 0 || $grades[$i] > 100) {
          $invalidGrades[] =  $grades[$i];
      } else if ($grades[$i] >= 0 && $grades[$i] <= 100) {
          $validGrades[] = $grades[$i];
      }
}

Answer 2

Try This

$grades = array(88,86,90,78,95,101,78,105,79,110);
$invalidGrades = array();
$validGrades = array();

foreach($grades as $grade) {
    if ($grade > 100 || $grade < 0) {
        array_push($invalidGrades, $grade);
    } else {
        array_push($validGrades, $grade);
    }
}

print "Grades";
print_r($grades);
print "invalidGrades";
print_r($invalidGrades);
print "validGrades";
print_r($validGrades);

You should get the following.

php54s test.php 
Content-type: text/html

GradesArray
(
    [0] => -1
    [1] => -4
    [2] => -10
    [3] => 88
    [4] => 86
    [5] => 90
    [6] => 78
    [7] => 95
    [8] => 101
    [9] => 78
    [10] => 105
    [11] => 79
    [12] => 110
)
invalidGradesArray
(
    [0] => -1
    [1] => -4
    [2] => -10
    [3] => 101
    [4] => 105
    [5] => 110
)
validGradesArray
(
    [0] => 88
    [1] => 86
    [2] => 90
    [3] => 78
    [4] => 95
    [5] => 78
    [6] => 79
)

Answer 3

foreach is your best option here, try this:

//Some random grades
$grades = [1, -10, 90, 30, -3, 200, 300, 44];
$validGrades = array();
$inValidGrades = array();

foreach($grades as $grade){
  if($grade < 0 || $grade > 100){
    $inValidGrades[] = $grade;
  }else{
    $validGrades[] = $grade;
  }
}

//Test the output
echo "<pre>";
print_r($grades);
echo "<br>";
print_r($validGrades);
echo "<br>";
print_r($inValidGrades);

The output will be:

Array
(
    [0] => 1
    [1] => -10
    [2] => 90
    [3] => 30
    [4] => -3
    [5] => 200
    [6] => 300
    [7] => 44
)

Array
(
    [0] => 1
    [1] => 90
    [2] => 30
    [3] => 44
)

Array
(
    [0] => -10
    [1] => -3
    [2] => 200
    [3] => 300
)

Answer 4

This can be done with a simple if-else block. The only choice about how to construct it comes down to if you want to use one condition or two in the if expression.

Method #1: ( Output Demo ) ( Calculation Demo ) "Single Condition"

$grades=array(-4,-1,0,1,6,10,70,99,100,101,105,110);
foreach($grades as $grade){
    if( ($grade+1)*(101-$grade) > 0 ){  // ($grade minus negative [lower limit])*([upper limit] plus $grad)
        $validGrades[] = $grade;
    }else{
        $invalidGrades[] = $grade;
    }
}
var_export($validGrades);
echo "\n---\n";
var_export($invalidGrades);

Method #2: ( Output Demo ) "Double Condition"

$grades=array(-4,-1,0,1,6,10,70,99,100,101,105,110);
foreach($grades as $grade){
    if( $grade<0 || $grade>100 ){
        $validGrades[] = $grade;
    }else{
        $invalidGrades[] = $grade;
    }
}
var_export($validGrades);
echo "\n---\n";
var_export($invalidGrades);

Output (from either method)

array (
  0 => -4,
  1 => -1,
  2 => 101,
  3 => 105,
  4 => 110,
)
---
array (
  0 => 0,
  1 => 1,
  2 => 6,
  3 => 10,
  4 => 70,
  5 => 99,
  6 => 100,
)

*Notes:

1. There will be an unnoticeable difference in efficiency between the two methods; this is purely demonstrative.

2. The "Double Condition" can also be written with the "And" logical operator ( && ) as if( $grade<=100 && $grade>=0 ){ with the same effect.

3. Because the pass / fail comparison is determined in the if expression, there is no need to use an elseif expression -- this would be redundant.

4. foreach() is a more appropriate construct to loop with versus for because calling the count() function is avoided. This also prevents your coding error while trying to access the grades via their index.

5. Calling array_push() (as some other answers do) is unnecessary overhead -- not that it is actually going to impact your application. I like to avoid function calls when possible. Using [] syntax is the function-free alternative to array_push() .