What is the difference between c language and javascript

Difference: 1. C language is mainly compiled into machine language, and JavaScript is mainly interpreted and executed as a script by the interpreter; 2. The memory of C language needs to be manually managed by programmers, while the memory of JS is interpreted by the interpreter. It is managed by the processor; 3. C language is a statically typed language, and JS is a dynamically typed language; 4. There are closures in JS, but not in C language.

The operating environment of this tutorial: windows7 system, javascript1.8.5&&c99 version, Dell G3 computer.

What is C language?

C language is a process-oriented, abstract, general-purpose programming language that is widely used in low-level development. C language can compile and process low-level memory in a simple way. C language is an efficient programming language that only generates a small amount of machine language and can run without any operating environment support.

What is JavaScript?

JavaScript is a high-level, interpreted, literal scripting language. It is a prototype-based, function-first language. It is a multi-paradigm language. It supports object-oriented programming, command programming, and functional programming.

The similarities between c language and javascript:

Some lexical and syntax are the same. The design of JavaScript's lexical and syntax is based on Java, and the design of Java's lexical and syntax is based on C. The lexical and syntax that I think of for JavaScript, Java, C and C are the same:

1. Use a single equal sign as an assignment operator instead of an equality judgment operator, such as: a=b 1 represents "put The result of variable b 1 is assigned to variable a" instead of "the value of variable a is equal to the value of variable b 1";

2. The assignment operation is an expression and can be used as a value to participate in other operations, such as (a=b 1)>10;

3. The statement ends with a semicolon;

4.It starts with “0x” to represent the hexadecimal number;

5. Use "&", "|", "^", "!", "&&" and "||" as bitwise AND, bitwise OR, bitwise XOR, logical NOT, logical AND, and logical OR operations respectively. operator;

6, ternary operator composed of question mark and colon;

7, multiplication and division operators, addition and subtraction operators, comparison operators, logical and logical or operators, assignment The priority order of operators;

8. The syntax of function call is "function name (parameter 1, parameter 2, ...)";

9. Code blocks are placed within curly brackets;

10. Grammar of if, for, while, do-while, switch-case, break;...

The difference between c language and javascript:

1. C language is mainly compiled into machine language, while JavaScript is mainly interpreted and executed as a script by the interpreter;

2. C language requires programmers to manually manage memory (mainly refers to the application of heap memory and release), while JavaScript memory is managed by the interpreter;

3. C language is a statically typed language, that is, the data type of each variable is determined before the program is run and cannot be changed during runtime. , and JavaScript is a dynamically typed language, and the data type of variables can still change at runtime;

4. There is no concept of closure in C language, and functions in JavaScript are composed of variables that can be accessed when they are defined. Closure;

5. C language does not support object-oriented features such as "class member methods", "class member encapsulation (invisible to the outside)", "class inheritance and polymorphism", and JavaScript can achieve object-oriented inheritance, polymorphism and encapsulation through prototype chains and closures. JavaScript that implements ECMAScript 2015 and above supports the definition of classes at the grammatical level;

6. C language can Calling the system API to implement multi-threading can improve the CPU utilization during blocking operations (mainly IO), while JavaScript is mainly single-threaded, and all possible blocking operations in JavaScript are handled by the asynchronous API provided by the JavaScript runtime. Complete

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