Convert float to string in php?

php string floating-point type-conversion

67,354

Solution 1

echo number_format($float,0,'.','');

note: this is for integers, increase 0 for extra fractional digits

Solution 2

$float = 0.123;
$string = sprintf("%.3f", $float); // $string = "0.123";

Solution 3

It turns out json_decode by default casts large integers as floats. This option can be overwritten in the function call:

$json_array = json_decode($json_string, , , 1);

I'm basing this only on the main documentation, so please test and let me know if it works.

67,354

tweety

Updated on November 29, 2020

Comments

tweety over 3 years

Like:

float(1.2345678901235E+19) => string(20) "12345678901234567890"

Can it be done?

(it's for json_decode...)
Ashith almost 13 years

This is a good solution if you want to have a maximum number of decimal places. Based on the question, I'd change the above to echo number_format($float,10,'.',''); giving it a max of 10 decimal places. (Arbitrary, but I'm pretty sure it should be higher than 0).
tweety almost 13 years

The json value I get is not float, it's a really big integer, like 23453453245324532453253425. But it gets converted to float by json_decode. Will your solution always get me the original json value? :) (it seems to work though for the data I have now)
Karoly Horvath almost 13 years

floats have a limited precision, once your integers are large enough it won't work. should work for approx 14 digits. beyond that it might work, but could be sheer luck.
tweety almost 13 years

The value has 17 numbers right now. Do you know when it will stop to precisely convert the float?
Ashith almost 13 years

You can change the setting in the function call, see my answer.
tweety almost 13 years

that's the first thing I tried - JSON_BIGINT_AS_STRING, and I get: json_decode expects at most 3 parameters bla bla... and a undefined constant message
Karoly Horvath almost 13 years

are these originally floats? because then they already lost precision. if they are ints try to send them as strings.
Ashith almost 13 years

Ha! I just tested and I got the same error, but with "expects at most 2 parameters". It looks like the 3rd parameter was added in 5.3 and the 4th in 5.4. So it would work if we upgraded our php.
netcoder almost 13 years

Anyway, it's not even valid code, you can't omit arguments like that.
Ashith almost 13 years

can't you? It says I passed in 4 parameters... Let me do a test.