How can I learn if 2 NSStrings are almost same to eachother?

How can I learn if 2 NSStrings are almost same to eachother?

References

Reference NO 1

http://stackoverflow.com/questions/15203301/how-can-i-learn-if-2-nsstrings-are-almost-same-to-eachother

Reference NO 2

http://stackoverflow.com/questions/10074298/how-to-check-if-two-strings-are-approximately-equal

Reference NO 3

http://rosettacode.org/wiki/Repeat_a_string

Reference NO 4

http://cocoadev.com/MethodSwizzling

Reference NO 5

http://www.objc.io/issue-3/advanced-auto-layout-toolbox.html

Reference NO 6

http://www.raywenderlich.com/5773/beginning-arc-in-ios-5-tutorial-part-2

Reference NO 7

#EANF#

Reference NO 8

#EANF#