All the combinations of "1, 2, 3, 4"
Some people search about "all the combinations of 1234". If we read it literally it means that they want to know all the combinations of only one number (1234). If there is only one number (no matter what number is it -- "1", "33", "104", "1200", "0.234", "0.000000000018", "494873294798377682638764287642836" or "1234") there are no combinations because one is one and you can't combine it with something else. So, we just can suppose that in fact, those people are searching for the all possible combinations of "1, 2, 3 and 4". This is easy. There are only 24 combinations. And here you may see them:
1234
1243
1324
1342
1423
1432
2134
2143
2314
2341
2413
2431
3124
3142
3214
3241
3412
3421
4123
4132
4213
4231
4312
4321.