Is there an eval execution function in jquery?

There is no eval execution function in jquery; eval is used to calculate JavaScript strings and is a function in JavaScript. This function can be executed as script code. If the parameter is an expression, the eval function will execute the expression. If the parameter is a JavaScript statement, the function will execute the specified statement, and the syntax is "eval (string)".

The operating environment of this article: Windows 10 system, jquery version 3.6.0, Dell G3 computer.

There is no eval execution function in jquery

eval() Definition

eval() function is used to calculate or execute parameters. If the argument is an expression, eval() evaluates the expression. If the argument is one or more JavaScript statements, eval() executes these statements

expressions and js statements

js expression: an expression produces a value, such as

• a

• 1 1

• demo(1)

• x === y ? 'a' : 'b',

js statement: js codes are all js statements (of course including js expressions), if judgments and for loops All are considered js statements

1. if(){}

2. for(){}

eval() uses

• JavaScript can interpret and run a string composed of JavaScript source code through the global function eval()

• It will compile the string as JavaScript code. If If compilation fails, a syntax error exception is thrown

• If the Javascript code passed to eval() generates an exception, eval() will pass the exception to the caller.

• The string passed to eval() must be grammatically valid. You cannot paste arbitrary code snippets into the function through eval(). For example: eval('return;') is It is meaningless, because return only plays a role in functions

• If the compilation is successful, this code will be executed and the last expression or statement in the string will be returned. The value of , if the last expression or statement has no value, it eventually returns undefined.

• The string in eval() executes in the same context as the calling function

Parameters

eval() has only one parameter which is a JavaScript expression, variable, statement or sequence of statements of string type.

If the parameter passed in is not a string, it returns this function directly.

Scope

eval() executes JavaScript code or defines variables/functions consistent with the code in the local scope. If a function defines a local variable b and then calls eval('b'), it returns the value of the local variable.

If it calls eval('a=1'), it will change the value of the local variable.

If the function calls eval('var b=2;'), a new local variable b

is declared

Recommended related tutorials: jQuery video tutorial

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