The difference between using switch in a loop and using break and continue after executing a condition

The test code in this article uses JavaScript Language writing

break and continue Usage list

1.break

use break Statement can make the process jump out of switch Statement of body , It can also be used. break Statement terminates the loop body in the loop structure , So as to end the cycle of this layer ahead of time .
Instructions ：

（1） Only in circulation and switch In the body of a sentence break;

（2） When break In the circulatory body switch In the body of a sentence , It works just to get out of the way switch Statement of body , Does not terminate the execution of the loop body . If you want to force the execution of the loop body , It can be in the loop body , But it's not switch Set... In the statement break sentence , If certain conditions are satisfied, you will jump out of the loop .

2.continue

continue The function of the statement is to skip the remaining unexecuted statements in the body of this loop , Immediately carry out the next cycle condition determination , It can be understood as only ending this cycle .

Be careful ：continue Statement does not terminate the entire loop .

Use break give an example

From the print results, it is not difficult to see the use break, When the condition is met, in addition to executing switch sentence , It will also continue to execute the remaining unexecuted statements in the body of this loop

let fruit=["apple", "banana", "orange", "pear"]
for (let i = 0; i < fruit.length; i++) {
    
	switch (fruit[i]) {
    
		case "orange":
			console.log(" Hey, hey, hey ");
			break;
			// continue;
		default:
			break;
	}
	console.log("we have " + fruit[i]);
}

/*  Print the results  we have apple we have banana  Hey, hey, hey  we have orange we have pear */
	

Use continue give an example

It can be seen from the print results that switch Use after condition continue When , When the execution meets the condition switch After the statement , The remaining unexecuted statements in the loop body will be skipped , Execute next cycle

let fruit=["apple", "banana", "orange", "pear"]
for (let i = 0; i < fruit.length; i++) {
    
	switch (fruit[i]) {
    
		case "orange":
			console.log(" Hey, hey, hey ");
			// break;
			continue;
		default:
			break;
	}
	console.log("we have " + fruit[i]);
}

/*  Print the results  we have apple we have banana  Hey, hey, hey  we have pear */
	

extend , Used in multi-level nested loops continue

It can be seen from the above two single-layer cycle examples switch A condition of break It will not have a skip effect on the remaining statements in this cycle , and continue Meeting , So many cycles are in the deep cycle switch Use continue Will it affect the circulation of the outer layer , The answer is no ,

continue Only right “ The innermost layer ” Of “ This cycle ” take effect , Skip the rest of the loop body in this loop . For the next cycle 、 Or the outer circle , It won't work .

let fruit=["apple", "banana", "orange", "pear"]
for (let j = 0; j < fruit.length; j++) {
    
	for (let i = 0; i < fruit.length; i++) {
    
		switch (fruit[i]) {
    
			case "orange":
				console.log(" Hey, hey, hey ");
				// break;
				continue;
			default:
				break;
		}
		console.log("we have " + fruit[i]);
	}
}
/*  Print the results   Four times the same ： we have apple we have banana  Hey, hey, hey  we have pear */