Summary of definitions and usage of constants

The define() function defines a constant. The function of the define() function is to define a constant. Constants are much like variables, except for the following differences: Constants [constant] and variables [variable] have many similarities, so it is easy to confuse them; below, we list the differences between constants [constant] and variables [variable] difference: •A constant's value cannot be changed after it is set A constant value cannot be changed after it is specified;•Constant names do not need a leading dollar sign ($) When setting a constant, there is no need to add a "$" sign in front; •Constants can b1. In-depth php defi

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Introduction: The define() function defines a constant. The function of the define() function is to define a constant. Constants are much like variables, except for the following differences: Constants [constant] and variables [variable] have many similarities, so they are easy to confuse; below, we list the constants [constant]...

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##Introduction: The define() function defines a constant. The function of the define() function is to define a constant. Constants are much like variables, except for the following differences: Constants [constant] and variables [variable] have many similarities, so they are easy to confuse; below, we list the constants [constant]...

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