PHP函数如何用函数实现两个数的比较 PHP函数数值比较功能的入门应用技巧​

strcmp

>

<

==

>=

<=

!=

$a = 10;
$b = 5;

if ($a > $b) {
  echo "a 大于 b";
} elseif ($a < $b) {
  echo "a 小于 b";
} else {
  echo "a 等于 b";
}

strcmp

strcmp

$a = "10";
$b = "5";

$result = strcmp($a, $b);

if ($result > 0) {
  echo "a 大于 b";
} elseif ($result < 0) {
  echo "a 小于 b";
} else {
  echo "a 等于 b";
}

strcmp

intval()

floatval()

function compareNumbers($a, $b) {
  if ($a > $b) {
    return 1;
  } elseif ($a < $b) {
    return -1;
  } else {
    return 0;
  }
}

$a = 10;
$b = 5;

$result = compareNumbers($a, $b);

if ($result > 0) {
  echo "a 大于 b";
} elseif ($result < 0) {
  echo "a 小于 b";
} else {
  echo "a 等于 b";
}

compareNumbers

==

$a = 0.1 + 0.2;
$b = 0.3;

if ($a == $b) {
  echo "相等";
} else {
  echo "不相等"; // 实际输出
}

$a

$a = 0.1 + 0.2;
$b = 0.3;
$tolerance = 0.000001; // 定义一个容差值

if (abs($a - $b) < $tolerance) {
  echo "相等"; // 实际输出
} else {
  echo "不相等";
}

abs()

$a = 10;
$b = "10";

if ($a == $b) {
  echo "相等"; // 实际输出
}

$a

$b

==

$b

===

===

$a = 10;
$b = "10";

if ($a === $b) {
  echo "相等";
} else {
  echo "不相等"; // 实际输出
}

$a

$b