for Statement

for Statement

The for statement is similar to the while statement, but more elaborate.

The syntax is as follows.

for(clause1;clause2;clause3) statement or block

Clause 1 specifies an expression to execute before entering the loop. You can also declare variables here; variables declared here remain valid for the duration of the loop (they are removed when the loop exits). It can be omitted.

Clause 2 specifies the condition. The statement or block is executed repeatedly while this condition is true. If omitted, it is treated as always true.

Clause 3 specifies an expression to execute at the end of the statement or block. It can be omitted.

The behavior is as follows:

(1) First, execute clause 1

(2) Evaluate clause 2; if it is false, finish without executing the statement or block

(3) Execute the statement or block

(4) Execute clause 3

(5) Evaluate clause 2; if it is false, exit the loop

(6) Repeat from (3)

If a **break** statement is encountered in the block, the loop exits at that point. If a **continue** statement is encountered, execution jumps to (4).

    var i,a=1;
    for(i=1;i<5;i++)
    {
        a*=i;
    }

    var i;
    for(i=0;i<10;i++)
    {
        if(obj[i]==0) continue; // i++ is still executed after continue
        if(obj[i]==1) break; // break exits immediately
        func(obj[i]);
    }