Php – Show a number to two decimal places

formattingnumber-formattingnumbersPHProunding

What's the correct way to round a PHP string to two decimal places?

$number = "520"; // It's a string from a database

$formatted_number = round_to_2dp($number);

echo $formatted_number;

The output should be 520.00;

How should the round_to_2dp() function definition be?

Best Answer

You can use number_format():

return number_format((float)$number, 2, '.', '');

Example:

$foo = "105";
echo number_format((float)$foo, 2, '.', '');  // Outputs -> 105.00

This function returns a string.

Related Solutions

Javascript – Validate decimal numbers in JavaScript – IsNumeric()

@Joel's answer is pretty close, but it will fail in the following cases:

// Whitespace strings:
IsNumeric(' ')    == true;
IsNumeric('\t\t') == true;
IsNumeric('\n\r') == true;

// Number literals:
IsNumeric(-1)  == false;
IsNumeric(0)   == false;
IsNumeric(1.1) == false;
IsNumeric(8e5) == false;

Some time ago I had to implement an IsNumeric function, to find out if a variable contained a numeric value, regardless of its type, it could be a String containing a numeric value (I had to consider also exponential notation, etc.), a Number object, virtually anything could be passed to that function, I couldn't make any type assumptions, taking care of type coercion (eg. +true == 1; but true shouldn't be considered as "numeric").

I think is worth sharing this set of +30 unit tests made to numerous function implementations, and also share the one that passes all my tests:

function isNumeric(n) {
    return !isNaN(parseFloat(n)) && isFinite(n);
}

P.S. isNaN & isFinite have a confusing behavior due to forced conversion to number. In ES6, Number.isNaN & Number.isFinite would fix these issues. Keep that in mind when using them.

Update : Here's how jQuery does it now (2.2-stable):

isNumeric: function(obj) {
    var realStringObj = obj && obj.toString();
    return !jQuery.isArray(obj) && (realStringObj - parseFloat(realStringObj) + 1) >= 0;
}

Update : Angular 4.3:

export function isNumeric(value: any): boolean {
    return !isNaN(value - parseFloat(value));
}

Javascript – How to convert decimal to hexadecimal in JavaScript

Convert a number to a hexadecimal string with:

hexString = yourNumber.toString(16);

And reverse the process with:

yourNumber = parseInt(hexString, 16);

Best Answer

Related Solutions

Javascript – Validate decimal numbers in JavaScript – IsNumeric()

Javascript – How to convert decimal to hexadecimal in JavaScript

Related Topic