Simple Case First

Simple Case First

This method is similar to common case first — the idea is to test the simplest condition first. More complicated and time-consuming computations can be avoided if the first test succeeds (or fails, depending on the context). This idea appears in two main situations:

• if-if construct (nested if statements), and
• logical operators (&& and ||).

The simplest test should be the first of a pair of nested if statements and should also be the first operand of a && or || operator. In the examples below, the sub-expression “x!=0” is evaluated first because it is the simplest and hence the least expensive to evaluate. This is the nested-if example:

    if (x != 0) {
        if (expensive_fn(x) != 0) {
            // ...
        }
    }

This is the && short-circuiting method:

    if (x != 0 && expensive_fn(x) != 0) {
        // ...
    }

• Next: • Up: Table of Contents • Buy: Generative AI in C++: Coding Transformers and LLMs

The new AI programming book by Aussie AI co-founders: AI coding in C++ Transformer engine speedups LLM models Phone and desktop AI Code examples Research citations Get your copy from Amazon: Generative AI in C++