To test for equality is ==
A warning: Beware of using "=" instead of "==", such as writing accidentally
if ( i = j ) .....
This is a perfectly LEGAL C statement (syntactically speaking) which copies the value in "j" into "i", and delivers this value, which will then be interpreted as TRUE if j is non-zero. This is called assignment by value - a key feature of C.
Not equals is: !=
Other operators < (less than) , > (grater than), <= (less than or equals), >= (greater than or equals) are as usual.