Php character comparison strcmp () function usage

The strcmp () function is used to compare two strings. if the two strings are completely equal, 0 is returned. otherwise, various return values are returned. This function is case-sensitive and can be used as a reference. The return value after comparison indicates that if str1 and str2 are equal, 0 is returned.

The strcmp () function is used to compare two strings. if the two strings are completely equal, 0 is returned. otherwise, various return values are returned. This function is case-sensitive and can be used as a reference.

Return value after Comparison

If str1 and str2 are equal, 0 is returned.

If str1 is smaller than str2, return <0 (but not necessarily scheduled-1, many online say-1, it is incorrect, the specific value size depends on the actual situation ).

If str1 is greater than str2, return> 0 (but different timing 1, the specific value size depends on the actual situation ).

The instance code is as follows:

1. Strcmp (date ('Y-m-D', $ user-> last_time), date ("Y-m-d", time () = 0
2. If case insensitive

Strncasecmp is used to compare a part of a case-insensitive string. it starts from the beginning of the string and the third parameter is the length to be compared:

The instance code is as follows:

1. Echo strncasecmp ("abcdd", "abcde", 3 );
2. // Return 0, which compares abc and abc. The two are the same because they are case insensitive.

We can also use = to compare php strings, as shown in

The instance code is as follows:

1. $ A = 'a ';
2. $ B = 'www .phpfensi.com ';
3. If ($ a = $ B)
4. {
5. Echo 'Equality ';
6. }
7. Else
8. {
9. Echo 'unequal ';
10. }

You can also use = to compare

The instance code is as follows:

1. 22 = "22"; // return true
2. 22 = "22"; // Return false