PHP `print` vs. `echo`: Which Output Function Should You Use?

The Nuances of PHP's print and echo

Despite superficially appearing as distinct constructs, PHP's print and echo share a common underlying implementation - the echo handler. However, a deeper dive reveals subtle differences between the two that determine their usage and suitability in various scenarios.

Syntactical Differences

• print expr is an expression that evaluates to a value and can be used within larger expressions.
• echo expr is a statement that simply outputs the expression's value to an output buffer.

Semantic Differences

• print e evaluates and type-casts e to a string, then streams it to the output buffer and returns 1.
• echo e is equivalent to print e, but does not have a return value.

Runtime Considerations

• print incurs a slight overhead due to the need to populate a return variable.
• echo directly delegates the printing task to the echo handler without any additional overhead.

Syntax and Use Cases

• Syntax: print expr vs. echo expr, expr, ..., expr

• Use Cases:

  • print is useful where a return value is needed, such as conditional expressions or obtaining an expression's result value.
  • echo is better suited for simple output, as it supports multiple arguments and does not have a return value.

Which Construct to Use?

In web applications, it's common practice to use echo since templates typically leverage the = syntax, which is an alias of echo. Moreover, echo is more efficient when printing multiple expressions without concatenation and has a smaller runtime overhead. Therefore, echo is the preferred choice for most output tasks.

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