QuickPerformanceCheck

// IF case
DateTime dt = DateTime.now();
Integer j = 0;
for(Integer i = 0; i < 100000; i++) {
    String s = 'str' + i*i + '-' + (i-12);

    String s2 = 'str' + (i+(i-1)*i)+ '-' + (i-3*4);
    if(s == s2) {}
    if(i == j) {}
    j++;
}
DateTime dt2 = DateTime.now();
System.debug(dt2.getTime() - dt.getTime());
//AVG 4680

// ASSERT case
DateTime dt = DateTime.now();
Integer j = 0;
for(Integer i = 0; i < 100000; i++) {
    String s = 'str' + i*i + '-' + (i-12);

    String s2 = 'str' + (i+(i-1)*i)+ '-' + (i-3*4);
    System.assert(s == s2);
    System.assert(i == j);
    j++;
}
DateTime dt2 = DateTime.now();
System.debug(dt2.getTime() - dt.getTime());
//AVG 5212