37 lines
		
	
	
		
			796 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			37 lines
		
	
	
		
			796 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| ---
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| title: Conditional Ternary Operators
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| localeTitle: 条件三元运算符
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| ---
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| ## 条件三元运算符
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| 
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| ### 基本用法
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| 
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| 三元运算符是在表达式中编写if-else的紧凑方法。
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| 
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| ```js
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| const thing = (condition) ? <if true> : <if false>; 
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| ```
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| 
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| 例如
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| 
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| ```js
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| const cappedInput = input > 50 ? 50 : input // this will cap the input at 50 
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| ```
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| 
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| ### 否则,如果
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| 
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| 你也可以链接三元运算符,这样你就会有一个if-else if-else行为
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| 
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| ```js
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| <first condition> ? <value if first true> 
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|  : <second condition> ? <value if second is true> 
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|  : <fallback value> 
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| ```
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| 
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| > **专业提示** :如您所见,您可以在多行上拆分三元运算符 例如
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| ```
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| const wealth = housesOwned > 3 ? "rich" 
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|              : housesOwned > 1 ? "nothing to complain" 
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|              : "poor" 
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| 
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| ``` |