fftshift in MATLAB

%Code:-

clc

clear all

close all

N=256;

n=0:255;

w=2*pi/N;

x=cos(5*w*n);

X = fft(x,256);

w = 0:2*pi/N:2*pi-2*pi/N;

w=w-pi;

subplot(2,1,1);

stem(n,x);

subplot(2,1,2);

y=fftshift(X);

stem(w,abs(y));