?? ??? ??: Daria Kraplak

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TypeScript? ??
JavaScript? TypeScript ??
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TypeScript? ???? ???? ?? ?? JavaScript? ?? ???? ?????! JavaScript? 1995?? ?????? ??? ?? ????? ?? ??????.

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??? ???? ?? ??? ?????. ??????? JavaScript? ???? ?? ??? JavaScript? ??? ???? ? ?? ??? ????. TypeScript? ??? ?? ? ?? ?? ?? ?????!

TypeScript? ??

TypeScript? JavaScript? ?? ?????. ??? ??? ?????? ??, ?? ?????? TypeScript? ?? JavaScript ??? ???? ? ???? ??? ????? ??? ????. ???? ???? TypeScript? ?? ??? ???? JavaScript ???? ????. ?? ??? ??? ?? ? ??? ?? ??? ??? ???? ?????? ?????. ?? ?? ?? ???? ??? ???? ??? JavaScript? ????? ?? ???? ??? ???? ? ?????.

JavaScript? TypeScript ??

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JavaScript?? ??? ??? ? ?? ??? ??? ??? ?? ?? ??? ? ????. ??? ??? ??? TypeScript? ?? ????? ????? ????? TypeScript? ???? ?? ??????. ??? ??? ??? ??? ? ??? ????? ???? ?? ?? ?? ??? ? ? ????!

// JavaScript 
let x = 6;  // x stores a number value.  
x = "Hello there";  // x is now storing a string value.  
// This is valid since JavaScript allows dynamic type reassignment.  

// TypeScript 
let x = 6;  // x stores a number value.  
// (For line below) Error: Type string is not assignable to type number.  
x = "Hello there";  
// The reassigned value below matches the inferred or declared type of 
// the variable. TypeScript is okay with this.  
x = 8;  

// For both 
// x stores a number value and does not allow reassignment here. 
const x = 20; 
// Error: Cannot assign to 'x' because it is a constant.  
x = 25; 

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? ?? ??? ?? TypeScript?? ??? ??? ??? ????? ??? ? ?? ? ?? ??? ?? ??? ???? ????. ?? ?? ??? ??? ? ??? ??(: )? ???? ?? ?????.

// JavaScript 
let x = 6;  // x stores a number value.  
x = "Hello there";  // x is now storing a string value.  
// This is valid since JavaScript allows dynamic type reassignment.  

// TypeScript 
let x = 6;  // x stores a number value.  
// (For line below) Error: Type string is not assignable to type number.  
x = "Hello there";  
// The reassigned value below matches the inferred or declared type of 
// the variable. TypeScript is okay with this.  
x = 8;  

// For both 
// x stores a number value and does not allow reassignment here. 
const x = 20; 
// Error: Cannot assign to 'x' because it is a constant.  
x = 25; 

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TypeScript?? "??"? ??? ?????? ?? ??, ???? ?? ????? ??? ??? ????. ??? "??"? ??? "??" ?? ??? ?????. ??? ??? ????? ?? ?? ?? ???? ??? ??? ????? ???? ???. JavaScript? ?? ?? ???? ??? ???? ??? ??? ??? ? ????. ??? TypeScript? ??? ??? ??? ????? ???? ???. ?? ??? ??? ?? ???? ??? ?? ????.

// JavaScript 
// No need to state the data type here, just assign the variable a value. 
let color = ‘purple’;
// Since JavaScript is flexible, it is fine with this reassignment. 
color = ‘blue’;
// This is also the case even if the value changes to 10. 

// TypeScript 
// 'color' is declared and expected to have a string value.  
let color: string;
// Similar to the line above, except we assign a value as well.  
let color: string = 'red';
color = ‘purple’;  // 'purple' is a string value, so this is valid.  
color = ‘blue’;  // 'blue' is a string value, so this is valid.  

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???? TypeScript? ?? ?? ???? ??????. ?? JavaScript? ?? ??? ?? ? ? ?? ?? ??? ???? ? ???? ?????? ??? ?????. ?? ? ?? ?? ??? ??? ? JavaScript ????? ???? ????!

? ??? JavaScript? ?? ????/?? ??? TypeScript? ???? ? ??? ?? ??? ????. ??? ? ? ???? ?? ??? ?? ??? ?? ??????

? ??? TypeScript? ???? ????? ??? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!