Sprintf php 2 decimal places
If still somebody reach this page with similar problems where floating number subtraction causes error or strange values. I want to explain this problem with a bit more details. The culprit is the floating point numbers. And different operating systems and different versions of programming languages can behave differently. Show
To illustrate the problem, I will explain why with a simple example below. It is not directly related to PHP and it is not a bug. However, every programmer should be aware of this issue. This problem even took many lives two decades ago. On 25 February 1991 this problem in floating number calculation in a MIM-104 Patriot missile battery prevented it intercepting an incoming Scud missile in Dhahran, Saudi Arabia, contributing to the death of 28 soldiers from the U.S. Army's 14th Quartermaster Detachment. But why it happens? The reason is that floating point values represent a limited precision. So, a value might not have the same string representation after any processing. It also includes writing a floating point value in your script and directly printing it without any mathematical operations. Just a simple example:
You would expect it to print 0.01, right? But it will print a very strange answer like 0.009999999999998 Like other numbers, floating point numbers double or float is stored in memory as a string of 0's and 1's. How floating point differs from integer is in how we interpret the 0's and 1's when we want to look at them. There are many standards how they are stored. Floating-point numbers are typically packed into a computer datum as the sign bit, the exponent field, and the significand or mantissa, from left to right.... Decimal numbers are not well represented in binary due to lack of enough space. So, uou can't express 1/3 exactly as it's 0.3333333..., right? Why we can't represent 0.01 as a binary float number is for the same reason. 1/100 is 0.00000010100011110101110000..... with a repeating 10100011110101110000. If 0.01 is kept in simplified and system-truncated form of 01000111101011100001010 in binary,when it is translated back to decimal, it would be read like 0.0099999.... depending on system (64bit computers will give you much better precision than 32-bits). Operating system decides in this case whether to print it as it sees or how to make it in more human-readable way. So, it is machine-dependent how they want to represent it. But it can be protected in language level with different methods. If you format the result, echo number_format(0.009999999999998, 2); it will print 0.01. It is because in this case you instruct how it should be read and how precision you require. Created: April-29, 2020 | Updated: December-10, 2020 In this article, we will introduce methods to show a
Use number_format() Function to Show a Number to Two Decimal Places in PHPThe built-in function
Example Codes:
This function has three optional parameters but it does not allow three parameters. It allows one, two, and four parameters to be passed. In this example, the Output:
Use round() Function to Show a Number to Two Decimal Places in PHPThe
Example Codes:
The important thing to note here is that it does not affect a number or a float value with one decimal point if we want to round these to two decimal places. Output:
Attention When the original number has fewer decimal digits than the decimal places to be formatted, You should use the Use sprintf() Function to Show a Number to Two Decimal Places in PHPThe built-in function
The
parameter
Here, we have used Output:
Related Article - PHP NumberHow can I get only 2 decimal places in PHP?php $num = 67; $number = sprintf('%. 2f', $num); echo "The number upto two decimal places is $number"; ?>
How does PHP calculate float value?Dealing with floating-point calculations in PHP. 1 – work on Integers. echo intval((0.1*10) + (0.7*10)); // int(8) ... . 2 – the round() function. echo intval(round((0.1+0.7)*10, 0)); // int(8) ... . 3 – casting to string. echo intval(strval((0.1+0.7)*10)); // int(8) ... . 4 – BC Math. ... . Summary.. How do I put 2 decimal places in HTML?1. DecimalFormat(“0.00”) We can use DecimalFormat("0.00") to ensure the number is round to 2 decimal places.
What is precision PHP?Precision is defined as the number of significant digits, and scale is the number of digits behind the decimal point. This means that a number like “1.23E-1000” would require a scale of 1002 but a precision of 3. Decimal uses precision, where bcmath uses scale.
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