﻿ PHP Math Exercise: Get random float numbers - w3resource

# PHP Math Exercises: Get random float numbers

## PHP math: Exercise-10 with Solution

Write a PHP function to get random float numbers.

Pictorial Presentation:

Sample Solution:

PHP Code:

``````<?php
function rand_float(\$st_num=0,\$end_num=1,\$mul=1000000)
{
if (\$st_num>\$end_num) return false;
return mt_rand(\$st_num*\$mul,\$end_num*\$mul)/\$mul;
}
echo rand_float()."\n";
echo rand_float(0.6)."\n";
echo rand_float(0.5,0.6)."\n";
echo rand_float(0,20)."\n";
echo rand_float(0,3,2)."\n";
echo rand_float(0,2,20)."\n";
?>
```
```

Sample Output:

```0.613314
0.886207
0.57955
17.570268
1.5
1.6
```

Flowchart :

PHP Code Editor:

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## PHP: Tips of the Day

PHP represents "no value" with the null keyword. It's somewhat similar to the null pointer in C-language and to the NULL value in SQL.

Setting the variable to null:

Example:

```\$nullvar = null; // directly
function doSomething() {} // this function does not return anything
\$nullvar = doSomething(); // so the null is assigned to \$nullvar
```

Checking if the variable was set to null:

```if (is_null(\$nullvar)) { /* variable is null */ }
if (\$nullvar === null) { /* variable is null */ }
```

Null vs undefined variable

If the variable was not defined or was unset then any tests against the null will be successful but they will also generate a Notice: Undefined variable: nullvar:

```\$nullvar = null;
unset(\$nullvar);
if (\$nullvar === null) { /* true but also a Notice is printed */ }
if (is_null(\$nullvar)) { /* true but also a Notice is printed */ }
```

Therefore undefined values must be checked with isset:

```if (!isset(\$nullvar)) { /* variable is null or is not even defined */ }
```