PHP - number_format fails with math operations

Question

The PHP function number_format produces weird results when using it with math operations.

Run this...

echo number_format(32545000 - 24343400) . '<br>';
echo number_format(32545000) - number_format(24343400);

Why does the second one produce an answer of "8" instead of the correct answer?

You don't want to be using `-` with strings. :) – alex Sep 28 '13 at 17:16 — alex, Sep 28 '13 at 17:16

score 5 · Accepted Answer · answered Sep 28 '13 at 17:14

5

number_format(32545000) returns a string: 32,545,000

number_format(24343400) returns a string: 24,343,400

The strings are converted to int and you get:

32 - 24 = 8

answered Sep 28 '13 at 17:14

pNre

Ok. But why wouldn't this work: `echo intval(number_format(32545000)) - intval(number_format(24343400));` – gtilflm Sep 28 '13 at 17:24
@gtilflm this code gives exactly the same result. `number_format` formats a number into a print-friendly format. Why would you subtract strings instead of doing `32545000 - 24343400`? – pNre Sep 28 '13 at 17:25

1 Answers1